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Bond Dissociation Energies

In Simple Molecules

— —

——

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U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

NSRDS
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UNITED STATES DEPARTMENT OF COMMERCE

Maurice H. Stans, Secretary

NATIONAL BUREAU OF STANDARDS • Lewis M. Branscomb, Director

Bond Dissociation Energies in Simple Molecule

B. deB. Darwent

Department of Chemistry

The Catholic University of America

Washington, D.C. 20017

NSRDS-NBS 31

Nat. Stand. Ref. Data Ser., Nat. Bur. Stand. (U.S.), 31, 52 pages (Jan. 1970)

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Library of Congress Catalog Card Number: 70-602101
Foreword

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hi
Contents

Page Foreword Ill Introduction 1 References 2

Table of bond dissociation energies 9

IV
Bond Dissociation Energies in Simple Molecules

B. deB. Darwent

Bond dissociation energy values (kcal/mol) and (kj/mol) of simple compounds are tabulated from a literature review covering the years 1962—1966 inclusively. Some selected values which appeared

in the years 1956-1962 are also included. Organic compounds are excluded except those containing one carbon atom. The groups > CO and —CN are not considered to be organic.

The values are quoted Usually at 0 K or 298 K and refer to the gaseous state. They represent

the energy required to break a bond at the specified temperature with all substances in the zero vibrational state of the ground electronic state. The experimental method for the energy value listed is given and referenced in the table. A value recommended by the author is listed as the final value for each reaction.

Key words: Bond dissociation energy; gaseous state; inorganic simple compounds; recommended

value; zero vibrational state of the ground electronic state.

Introduction

This review of bond dissociation energies of

simple compounds includes values published, generally, between 1956 and 1966 inclusive. The

period from 1956 to 1962 was covered less thoroughly

than that of 1962 to 1966. Cottrell’s book [3]

1 appeared in 1958 and is assumed to have covered

the literature up to and including 1955; the compilation of Vedeneyev et al. [6] covered the field to 1962, but they did not attempt a complete cov- erage of the literature. In the present review all values appearing between 1962 and 1966, and se- lected values appearing between 1956 and 1962

have been given in the table, even if some of them

may now be considered to be inaccurate or completely untrustworthy. This approach is of some

value, especially for bonds on which only a few

measurements have been made, since opinions of

relative merit often change with time. The efficiency

of retrieval of information, within the stated period,

is estimated to be approximately 80 percent.

Organic compounds have been excluded, in view

of Kerr’s excellent review [8] of 1966, although

compounds containing one carbon atom have been

included; the groups > CO and — CN are not re- garded as being organic.

Very recent data on thermochemical properties

have been published by the National Bureau of

Standards as Technical Note 270-3 [9]; many bond

dissociation energies have been recalculated from

those data. It should be pointed out that the data

in Ref. [9] often include input from spectroscopic

and other types of measurements. Thus a dissociation energy labeled “Thermochemical; based on

[9]” in this tabulation is not necessarily derived

solely from conventional thermochemical measurements.

The bonds are listed alphabetically under the

more electropositive elements except for bonds

1 Figures in brackets indicate the literature references on page 2.

between H and other elements, which are given

under the other element. Thus data on O—H, H—Cl,

etc., are found under O, Cl, etc. The bond dissociation energy D° for a bond A—

which is broken through the reaction

AB~> A+B

is defined here as the standard-state enthalpy

change for the reaction at a specified temperature.

That is,

D° = WfS(A) + Atf/?(B) - AtffflAB)

where AHfo is the standard-state heat of formation.

All values of D° refer to the gaseous state, and are given at either 0 K or 298 K, and in some cases at both temperatures. The few exceptions are noted

under “Remarks ’. The value of D° at 0 K is equal

to the energy required to break the A—B bond under

the stipulated conditions that the reactant and

product molecules are in their electronic and vi- brational ground states. Thus it has a clearer physical interpretation than the dissociation energy at other temperatures. In the simplest case where the

bond of a diatomic molecule is broken, D° at 298 K

is greater then D° at 0 K by an amount which lies between RT and (3/2) RT (i.e. , 0.6 to 0.9 kcal/mol).

In polyatomic molecules this difference may be

somewhat greater.

The values of D° are listed in both kcal/mol and

kj/mol. The conversion factor is 1 kcal/mol = 4.184

kj/mol.

No attempt will be made here to describe or discuss the many methods used to measure bond

dissociation energies since that has already been

done [1 to 8]. It is well known that individual

methods are useful and reliable only for limited

types of molecules and over limited ranges of

conditions. Thus the classic static manometric

1
method gives excellent results for I2 , N2 O4 , etc. but not for dibenzyl; the spectroscopic method

gives values of the highest precision for simple

molecules, especially when the dissociation products are unequivocal and a clear convergence can

be obtained, but it is much less useful for more

complex molecules.

Many determinations of bond dissociation en- ergies have recently appeared using high temperatures chemistry techniques, e.g., effusion from a Knudsen cell and the use of mass spectrometry to identify and measure the concentrations of the effusing materials. Most of the measurements on the

oxides of the Group IIA elements have been made

by that technique and by flame photometry. In

theory both methods are capable of giving values of

at least modest precision for the bond dissociation

energies. Although in some cases the data so obtained are often consistent and fairly precise, in

other instances, e.g. CaO, there is considerable disagreement, not only between the two methods but

also between values obtained by the same method.

There has been much controversy on the relative

merits of these two techniques. The high temperature mass-spectrometry results are suspect [55]

because of the possibility of fragmentation of the

molecule under electron impact. In another review

[190] it is claimed that Drowart and Goldfinger

[10] had already refuted that suggestion. Actually,

Drowart and Goldfinger did not really disprove the

claim but rather stated that interaction with the

alumina container is likely to be a more important

source of uncertainty. On the other hand, there does

appear to be doubt concerning both the nature of

the emitter and the possibility of interference by

other substances in the flame photometric work.

At this stage the only safe conclusion is that much

more research is required.

The estimated uncertainties of individual meas- urements are those given by the original authors or reviewers. Recommended values are listed in bold

type with estimated uncertainties. Those estimates

are based on the extent of agreement between dif- ferent measurements, more weight being given to the results from the more reliable method, when the

datum results from a direct measurement. For

thermochemically calculated values consideration

is given to the precision of each of the thermochemical quantities involved in the calculation. No at- tempt has been made at a statistical evaluation of

uncertainties. They are to some extent the result of

my own prejudice, though often tempered by the

advice of experts.

The author is grateful to the Catholic University

of America for leave of absence and sabbatical

leave and to the National Bureau of Standards for

space and technical and financial assistance. The

space was provided by the Physical Chemistry

Division and the financial assistance by the Office of

Standard Reference Data, National Bureau of

Standards. It is indeed a pleasure to acknowledge

the help and advice given by Dr. D. Garvin of the

Elementary Processes Section and Dr. S. A.

Rossmassler of the Office of Standard Reference

Data. The author is greatly indebted to Dr. W. H.

Evans for many discussions and advice about

thermochemical measurements and to Dr. H. M.

Rosenstock for information on many matters,

mostly scientific.

References

[1] Gaydon, A., Dissociation Energies and Spectra of Diatomic

Molecules, 2nd ed., (Chapman and Hall, London, 1953).

[2] Szwarc, M., The determination of bond dissociation energies by pyrolytic methods, Chem. Rev., 47, 75 (1950).

[3] Cottrell. T. L., The Strengths of Chemical Bonds, (Butter- worths Scientific Publications, London, 1st ed., 1954, 2nd

ed., 1958).

[4] Herzberg, G., Molecular Spectra and Molecular Structure.

I. Spectra of Diatomic Molecules, 2nd ed. (D. Van Nostrand

Co., Inc., Toronto-New York-London, 1950).

[5] Sehon, A. H., and Szwarc, M., Bond energies, Ann. Rev.

Phys. Chem., 8, 439 (1957).

[6] Vedeneyev, V. I., Gurvich, L. V., Kondrat’yev, V. N., Medvedev, V. A., and Frankevich, Ye. L., Bond Energies,

Ionization Potentials and Electron Affinities (St. Martin’s

Press, New York, 1962).

[7] Wilkinson, P. G., Diatomic molecules of astrophysical

interest: ionization potentials and dissociation energies,

Astrophys. J., 138 , 778 (1963).

[8] Kerr, J. A., Bond dissociation energies by kinetic methods,

Chem. Rev., 66, 465 (1966).

[9] Wagman, D. D., Evans, W. H., Parker, V. B., Halow. I., Bailey, S. M., and Schumm. R. H., Selected values of chemical thermodynamic properties. Part 3. Tables for the first thirty-four elements in the standard order of arrangement,

Nat. Bur. Stand. (U.S.), Tech. Note 270-3 (1967) and Part 4. Tables for Elements 35 through 53 in the standard order of arrangement, Nat. Bur. Stand. (U.S.), Tech. Note 270-4

(1969).

[10] Drowart, J., and Goldfinger, P., High temperature chemistry, Ann. Rev. Phys. Chem., 13 , 459 (1962).

[11] Gurvich, L. V., and Ryabova, V. G., Dissociation energy of the BaCl molecule, Teplofizika Vysokikh Temperatur, 2,

215 (1964).

[12] Drummond, G., and Barrow. R. F., Thermochemical dis- sociation energies of gaseous calcium, strontium and

barium oxides. Trans. Faraday Soc., 47 , 1275 (1951).

[13] Inghram, M. G., Chupka, W. A., and Porter. R. F., Mass

spectrometric study of barium oxide vapor, J. Chem. Phys.,

23,2159 (1955).

[14] Stafford, F. E., and Berkowitz, J., Mass-spectrometric

study of the reaction of water vapor with solid barium oxide.

J. Chem. Phys., 40, 2963 (1964).

[15] Coomber, J. W., and W'hittle, E.. Bond dissociation energies

from equilibrium studies. Part 1. D(CF3 -Br), D(C2 F-Br) and

D(N-C3F7 -Br), Trans. Faraday Soc., 63 , 608 (1967).

[16] Van der Kelen, G. P.. and De Bievre, P. J., Studies on halo- genated aliphatic compounds. VI. The critical potentials of the principal ions in the mass spectra of the halogenated

acetonitriles. Bull. Soc. Chim. Beiges. 69 , 379 (1960).

[17] Gordon, R. D., and King, G. W., The emission spectrum of the CC1 radical. Can. J. Phys., 39 , 252 (1961).

[18] Reed, R. I., and Snedden, W.. Electron impact methods.

II. Latent heat of sublimation of carbon, Trans. Faraday

Soc. 54, 301 (1958).

[19] Fox, R. E., and Curran, R. K., Ionization processes in CCLi

and SFs by electron beams, J. Chem. Phys., 34, 1595

(1961).

2
[20] Lagerqvist, A., Westerlund, H., Wright, C. V., and Barrow,

R. F., Rotational analysis of the ultraviolet band system of CS, Arkiv Fysik, 14, 387 (1959).

[21] Ryabova, V. G., and Gurvich, L. V., Determination of dis- sociation energy of metal halides from equilibria in flames.

2. Dissociation energies of CaF, CaF2 , SrF and SrF2 , Teplofizika Vysokikh Temperatur, 2 , 834 (1964).

[22] Ryabova, V. G., and Gurvich, L. V., Investigation of the energy of the metal-hydroxyl bond in the CaOH, SrOH and

BaOH molecules, Teplofizika Vysokikh Temperatur, 3, 318

(1965).

[23] Ryabova, V. G., and Gurvich, L. V., Determination of the

dissociation energies of metal halides by investigating the equilibrium of reactions in flames. III. Dissociation energies of CaCl,CaCl2 , SrCl, SrCl2 and BaCl2 , Teplofizika

Vysokikh Temperatur, 3, 604 (652) (1965).

[24] Kopp, I., and Wirhed, R., On the B-X band system of BaD,

Arkiv Fysik, 32, 307 (1966).

[25] Kopp, I., Kronekvist, M., and Guntsch, A., Rotational analysis of the A-X band system of BaH and BaD, Arkiv Fysik,

32, 371 (1966).

[26] Kopp, I., Aslund, N., Edvinsson, G., and Lindgren, B., Rotational analysis of the perturbed C and D states of BaH

and BaD, Arkiv Fysik, 30, 321 (1965).

[27] Fisher, I. P., Mass spectrometry study of intermediates in thermal decomposition of perchloric acid and chlorine di- oxide, Trans. Faraday Soc., 63, 684 (1967).

[28] Johns, J. W. C., and Barrow, R. F., The Ultra-Violet Spectra

of HF and DF, Proc. Roy. Soc. (London), A251, 504 (1959).

[29] Drowart, J., and Honig, R. E., Mass spectrometric study of gallium and indium. Bull. Soc. Chim. Beiges, 66, 411

(1957).

[30] Drowart, J., and Honig, R. E., A mass spectrometric method

for the determination of dissociation energies of diatomic

molecules, J. Phys. Chem., 61, 980 (1957).

[31] Herzberg, G., and Monfils, A., The dissociation energies of the H2 , HD, and D2 Molecules, J. Mol. Spect., 5, 482 (1960).

[32] Wieland, K., Bandensysteme B( 22

+)—» X( 22

+

) und Dis- soziationswerte der Radikale HgJ und HgBr, Z. Elektro- chim., 64, 761 (1960).

[33] Durie, R. A., and Ramsay, D. A., Absorption spectra of the halogen monoxides. Can. J. Phys., 36, 35 (1958).

[34] Bulewicz, E. M., Phillips, L. E., and Sugden, T. M., Deter- mination of dissociation constants and heats of formation of simple molecules by flame photometry. Part 8. Stabilities of the gaseous diatomic halides of certain metals, Trans. Faraday Soc., 57, 921 (1961).

[35] Berkowitz, J., Meschi, D. J., and Chupka, W. A., Hetero- genous reactions studied by mass spectrometry. II. Reaction of Li2 0(s) with 1120(g), J. Chem. Phys., 33, 533 (1960).

[36] Altman, R. L., Vaporization of magnesium oxide and its reaction with alumina, J. Phys. Chem., 67, 366 (1963).

[37] Alexander, C. A., Ogden, J. S., and Levy, A., Transpiration

study of magnesium oxide, J. Chem. Phys., 39, 3057 (1963).

[38] Milton, E. R. V., Dunford, H. B., and Douglas, A. E., Spec- trum of NBr excited in active nitrogen, J. Chem. Phys., 35,

1202 (1961).

[39] Brown, L. M., and Darwent, B. deB., Spectrophotometric

determination of the rate of dissociation of tertrafluoro- hydrazine behind a shock wave, J. Chem. Phys., 42, 2158

(1965).

[40] Herman, L., Felenbock, P., and Herman, R., Spectre

d’emission des radicaux OH et OD, J. Phys. Radium, 22,

83 (1961).

[41] Purmal, A. P., and Frost, A. V., Energiia dissotsitsii ON,

Vestnik Moscov. Univ. Ser. n Khim. No. 1, 25 (1961).

[42] Forst, W., Second-order unimolecular kinetics in the thermal decomposition of hydrogen peroxide vapor. Can.

J. Chem., 36, 1308 (1958).

[43] Levy, J. B., and Copeland, B. K. W., The kinetics of the hydrogen-fluorine reaction. II. The oxygen-inhibited reaction, J. Phys. Chem., 69, 408 (1965).

[44] Blanchard, L., and LeGoff, P., Mass spectrometric study of

the Species CS, SO, and CC12 produced in primary hetero- geneous reactions, Can. J. Chem., 35, 89 (1957).

[45] McGrath, W. D., and McGarvey, J. F., Absorption spectrum

and dissociation energy of the SO radical, J. Chem. Phys.,

37, 1574 (1962).

[46] Gurvich, L. V., and Shenyavskaya, Ye. A., The electronic spectrum of scandium monofluoride, Optics and Spect.

(U.S.S.R.) 14, 161 (1963).

[47] Douglas, A. E., The spectrum of silicon hydride, Can. J. Phys., 35, 71 (1957).

[48] Gurvich, L. V., and Ryabova, V. G., Investigation of the

dissociation energies of BaO and BaOH, Opt. i Spektroskopiya, 18, (1965).

[49] Seal, K. E., and Gaydon, A. G., Shock-tube measurement of the dissociation energy of NH using absolute band intensities, Proc. Phys. Soc. (London), 89, 459 (1966).

[50] Mal’tsev, A. A., Kataev, D. I., and Takevskii, V. M., Study

of the electronic spectra and isotope effect of oxygen compounds of boron. III. Gamma bands of the BO molecules, Opt. i Spektroskopiya, 9, 713 (1960).

[51] Berkowitz, J., Correlation scheme for diatomic oxides, J. Chem. Phys., 30, 858 (1959).

[52] Veits, I. V., and Gurvich, L. V., Bond energy of the molecules of CaOH and SrOH, Opt. i Spektroskopiya, 2, 274

(1957).

[53] Hurley, A. C., Electronic structure of the first row hydrides.

III. Predissociation by rotation in the AGr state and the

dissociation energy of BH, Proc. Roy. Soc. (London), A261,

237 (1961).

[54] McKinney, C. N., and Innes, K. K., Emission spectra of the A1S molecule, J. Mol. Spect., 3,235 (1959).

[55] Medvedev, V. A., Dissociation energies and heats of sublimation of the oxides of alkaline earth metals, Zh. Fiz. Khim., 35, 1481 (1961).

[56] Kant, A., and Strauss, B., Dissociation energies of diatomic

molecules of the transition elements. II. Titanium, chromium, manganese and cobalt, J. Chem. Phys., 41, 3806

(1964).

[57] Armstrong, G. T., and Marantz, S., Heats of formation of two isomers of difluorodiazine, J. Chem. Phys., 38, 169

(1963).

[58] Verhaegen, G., and Drowart, J., Mass spectrometric deter- mination of the heat of sublimation of boron and of the

dissociation energy of B2 , J. Chem. Phys., 37, 1367 (1962).

[59] Curran, R. K., and Fox, R. E., Mass spectrometer investi- gation of ionization of N2 0 by electron impact, J. Chem.

Phys., 34, 1590 (1961).

[60] Dibeler, V. H., Reese, R. M., and Mann, D. E., Ionization and dissociation of perchlorylfluoride by electron impact,

J. Chem. Phys., 27, 176 (1957).

[61] Porter, R. F., and Spencer, C. W., Stabilities of the gaseous

molecules, BiSe, BiTe and SbTe, J. Chem. Phys., 32, 943

(1960).

[62] Ackerman, M., Stafford, F. E., and Verhaegen, G., Studies

of the vapors of the system Au-Cr and Au-Pd by mass

spectrometry, J. Chem. Phys., 36, 1560 (1962).

[63] Ackerman, M., Drowart, J., Stafford, F. E., and Verhaegen,

G., Mass spectrometric study of the gaseous molecules

above AgSn, AuSn, and CuSn Alloys, J. Chem. Phys., 36,

1557 (1962).

[64] Guttman, A., and Penner, S. S., Experimental determination of the heat of dissociation of N2 04 = 2N02 from the temperature dependence of absolute infrared intensities,

J. Chem. Phys., 36, 98 (1962).

[65] Flowers, M. C., and Benson, S. W., Kinetics of the gas- phase reaction of CH3I with HI, J. Chem. Phys., 38, 882

(1963).

[66] Burns, R. P., DeMaria, G., Drowart, J., and Inghram, M. G., Mass spectrometric investigation of the vaporization of

ln2 03 , J. Chem. Phys., 38, 1035 (1963).

[67] Prophet, H., Heat of formation of methylene, J. Chem.

Phys., 38, 2345 (1963).

[68] Ehlert, T. C., Blue, G. D., Green, J. W., and Margrave, J. L., Mass spectrometric studies at high temperatures. III. Dissociation energies of the alkaline earth monofluorides,

J. Chem. Phys., 41, 2250 (1964).

[69] Hildenbrand,D. L., and Murad, E., Dissociation energy of boron monofluoride from mass-spectrometric studies,

J. Chem. Phys., 43, 1400 (1965).

[70] Benson, S. W., Thermochemistry of the bromination of chloroform and the heat of formation of the CCL radical,

J. Chem. Phys., 43 , 2044 (1965).

[71] Kalff, P. J., Hollander, T. J., and Alkemade, C. Th. J.,

3
Flame-photometric determination of the dissociation energies of the alkaline-earth oxides, J. Chem. Phys., 43, 2299

(1965).

[72] Brebrick, R. F., Partial pressures in equilibrium with group IV tellurides. III. Germanium telluride, J. Chem. Phys., 41,

1140 (1964).

[73] Hildenbrand, D. L., and Theard, L. P., Effusion studies, mass spectra, and thermodynamices of beryllium fluoride vapor, J. Chem. Phys., 42 , 3230 (1965).

[74] Jacobs, T. A., Giedt, R. R., and Cohen, N., Kinetics of decomposition of HF in shock waves, J. Chem. Phys., 43,

3688 (1965).

[75] Singh, A. N., and Rai, D. K., On the dissociation energy of S2 and SO molecules, J. Chem. Phys., 43, 2151 (1965).

[76] Kant, A., Dissociation energies of diatomic molecules of the transition elements. I. Nickel, J. Chem. Phys., 41,

1872 (1964).

[77] Warneck, P., Marmo, F. F., and Sullivan, J. O., Ultraviolet absorption of S02 : Dissociation energies of S02 and SO,

J. Chem. Phys., 40, 1132 (1964).

[78] Carlson, K. D., and Nesbet, R. K., Wavefunctions and binding energies of the titanium monoxide molecule, J. Chem.

Phys., 41, 1051 (1964).

[79] Brewer, R. G., and Kester, F. L., Dissociation energy of the CH radical, J. Chem. Phys., 40, 812 (1964).

[80] Marquart, J. R., and Berkowitz, J., Dissociation energies of some metal sulfides, J. Chem. Phys., 39 , 283 (1963).

[81] Berkowitz, J., and Marquart, J. R., Equilibrium composition

of sulfur vapor, J. Chem. Phys., 39, 275 (1963).

[82] DeMaria, G., Drowart, J., and Inghram, M. G., Thermodynamic study of InSb with a mass spectrometer, J. Chem.

Phys., 31, 1076 (1959).

[83] DeMaria, G., Drowart, J., and Inghram, M. G., Mass spec- trometric study of A1203 , J. Chem. Phys., 30, 318 (1959).

[84] Cohn, R., and Drowart, J., Thermodynamic study of tin sulfide and lead sulfide using a mass spectrometer, J. Chem.

Phys., 37, 1120 (1962).

[85] Grimley, R. T., Burns, R. P., and Inghram, M. G., Thermodynamics of the vaporization of Cr2 03 : Dissociation energies of CrO, Cr02 , and Cr03 , J. Chem. Phys., 34, 664 (1961).

[86] Yoshimine, M., Computed potential curve and spectroscopic constants for beryllium oxide ground state in molecular orbital approximation,!. Chem. Phys., 40, 2970 (1964).

[87] Giguere, P. A., Revised values of the O—O and the O—

bond dissociation energies, J. Chem. Phys., 30, 322 (1959).

[88] Lindeman, L. P., and Guffy, J. C., Recalculation of D(HO—OH) Based on New Value of D(0—H), J. Chem.

Phys., 30, 322 (1959).

[89] Margrave, J. L., Use of mass spectrometric appearance

potentials in thermochemical calculations. I. Consistency

relationships for methane and substituted methanes, and

the heat of formation of CH3F, J. Chem. Phys., 24, 475

(1956).

[90] Inghram, M. G., Porter, R. F.. and Chupka, W. A., Mass

spectrometric study of gaseous species in the B—

2 03 system, J. Chem. Phys., 25 , 498 (1956).

[91] Ackerman, M., Stafford, F. E., and Drowart, J., Mass

spectrometric determination of the dissociation energies of the molecules AgAu, AgCu, and AuCu, J. Chem. Phys.,

33, 1784 (1960).

[92] Panish, M. B., and Reif, L., Thermodynamics of the vaporization of Hf and Hf02 : Dissociation energy of HfO, J. Chem.

Phys., 38, 253 (1963).

[93] Verhaegen, G., Smoes, S., and Drowart, J., Mass-spectrometric determination of the dissociation energy of the molecules Sc2 , Y2 , La>, and YLa, J. Chem. Phys., 37, 239

(1963).

[94] Rees, A. L. G., Electronic spectrum and dissociation energy of fluorine, J. Chem. Phys., 26, 1567 (1957).

[95] Schissel, P., Dissociation energies of Cu2 , Ag2 , Au2 , J. Chem.

Phys., 26, 1276 (1957).

[96] Goldstein, H. W., Walsh, P. N., and White, D.. Rare earths.

I. Vaporization of La2 03 and Nd2 03 : Dissociation energies

of gaseous LaO and NdO, J. Phys. Chem., 65, 1400 (1961).

[97] Kiser, R. W., and Hobrock, B. G., The ionization potential of hydrogen disulfide (H2 S2 ), J. Phys. Chem., 66, 1214

(1962).

[98] Tschuikow-Roux, E., Thermodynamic properties of

nitryl fluoride, J. Phys. Chem., 66, 1636 (1962).

[99] Berkowitz, J., Chupka, W. A., Blue, G. D., and Margrave,

J. L., Mass spectrometric study of the sublimation of lithium oxide, J. Phys. Chem., 63 , 644 (1959). [100] Porter, R. F., and Schoonmaker, R. C., A mass spectrometric study of the vaporization of ferrous bromide, J. Phys. Chem., 63 , 626 (1959). [101] Blackburn, P. E., Hoch, M., and Johnston, H. L., The

vaporization of molybdenum and tungsten oxides, J. Phys. Chem., 62 , 769 (1958).

[102] Gunn, S. R., Green, L. G., and Von Egidy, A. I., The heat

of chlorination of diboron tetrachloride, J. Phys. Chem.,

63, 1787 (1959). [103] Sullivan, J. H., The thermal reactions of hydrogen iodide with alkyl iodides, J. Phys. Chem. 65, 722 (1961). [104] Drowart, J., DeMaria, G., Burns, R. P., and Inghram,

M. G., Thermodynamic study of A12 03 using a mass spec- trometer, J. Chem. Phys., 32, 1366 (1960). [105] Foner, S. N., and Hudson, R. U., Mass spectrometric

detection of triazine and tetrazene and studies of the free radicals NH2 and N2 Hs, J. Chem. Phys., 29 , 442 (1958). [106] Dibeler, V. H., Reese, R. M., and Franklin. J. L., Ionization and dissociation of oxygen difluoride by electron impact,

J. Chem. Phys., 27, 1296 (1957). [107] Herron, J. T., and Dibeler, V. H., Mass spectrometric

study of the thermal dissociation of N2F4 , J. Chem. Phys.,

35, 747 (1961). [108] Drowart, J.. and Honig, R. F., Mass spectrometric study

of copper, silver, and gold, J. Chem. Phys., 25, 581 (1956). [109] Kiser, R. W., Estimation of the ionization potential and

dissociation energy of molecular astatine, J. Chem. Phys.,

33, 1265 (1960). [110] Loughran, E. D., and Mader, C., Appearance potential

study of tetrafluorohydrazine, J. Chem. Phys.. 32, 1578

(1960). [111] Foner, S. N., and Hudson, R. L., Ionization potential of the OH free radical by mass spectrometry, J. Chem.

Phys., 25, 602 (1956). [112] Brewer, L., Dissociation energy of S2 , J. Chem. Phys.,

31, 1143 (1959). [113] Marsden, D. G. H., Dissociation energies of SO and S2 , J. Chem. Phys., 31, 1144 (1959). [114] Wiedemeier, H.. and Gilles, P. W., Mass-spectrometrie

study of the sublimation of MnS(s) and the dissociation energy of MnS(g), J. Chem. Phys., 42, 2765 (1956). [115] Inghram, M. G., Chupka, W. A., and Berkowitz, J.. Thermodynamics of the Ta-0 system: The dissociation energies

of TaO and Ta02 , J. Chem. Phys., 27, 569 (1957). [116] Berkowitz, J., Chupka. W. A., and Inghram, M. G., Thermodynamics of the V-0 system: Dissociation energies of VO and V02 , J. Chem. Phys., 27, 87 (1957). [117] Reese, R. M., Dibeler, V. H., and Franklin, J. L., Electroi. impact studies of sulfur dioxide and sulfuryl fluoride. J. Chem. Phys., 29, 880 (1958). [118] Schoonmaker, R. C., and Porter, R. F., Mass spectrometric study of ferrous chloride vapor. J. Chem. Phys., 29,

116 (1958). [119] Foner, S. N.. and Hudson. R. L., Ionization and dissociation of hydrogen peroxide by electron impact. J. Chem.

Phys., 36, 2676 (1962). [120] Knight, H. T., and Rink, J. P., Dissociation energy of cyanogen and related quantities by X-ray densitometry

of Shock Waves, J. Chem. Phys., 35, 199 (1961). [121] Chupka, W. A., Berkowitz, J., and Inghram, M. G., Thermodynamics of the Zr-Zr02 system: The dissociation energies

of ZrO and Zr02 , J. Chem. Phys., 26, 1207 (1957). [122] Dibeler, V. H., Krauss, M., Reese, R. M., and Harllee,

F. N., Mass-spectrometric study of photoionization. III. Methane and methane-d4 , J. Chem. Phys., 42 , 3791

(1965). [123] Drowart, J., DeMaria, G., Boerboom, A. J. H., and Inghram,

M. G., Mass spectrometric study of inter-group IVB

molecules, J. Chem. Phys., 30, 308 (1959). [124] Farmer, J. B., Henderson, I. H. S., Lossing, F. P., and

Marsden, D. G. H., Free radicals by mass spectrometry.

IX. Ionization potentials of CF3 and CC13 radicals and

4
bond dissociation energies in some derivatives, J. Chem.

Phys., 24. 348 (1956).

1125] Pottie, R. F., and Lossing, F. P., Free radicals by mass

spectrometry. XXV. Ionization potentials of cyanoalkyl

radicals, J. Am. Chem. Soc., 83, 4737 (1961). [126] Johnson, F. A., and Colburn, C. B., The tetrafluorohydra- zine-difluoroamino radical equilibrium, J. Am. Chem.

Soc. 83, 3043 (1961).

[127] Dibeler, V. H., Reese, R. M., and Franklin, J. L., Mass

spectrometric study of cyanogen and cyanoacetylenes,

J. Am. Chem. Soc., 83, 1813 (1961).

[128] Dibeler, V. H., Franklin, J. L., and Reese, R. M., Electron impact studies of hydrazine and the methyl-substituted

hydrazines, J. Am. Chem. Soc., 81, 68 (1959). [129] Milne, T. A., and Gilles, P. W., The dissociation energy

of fluorine and the magnetic deflection of its molecular

beams, J. Am. Chem. Soc., 81, 6115 (1959). [130] Franklin, J. L., Dibeler, V. H., Reese, R. M., and Krauss,

M., Ionization and dissociation of hydrazoic acid and

methyl azide by electron impact, J. Am. Chem. Soc., 80, 298 (1958). [131] Calvert, J. G., and Gruver, J. T., A kinetic study of the thermodynamic properties of the acetyl free radical, J. Am. Chem. Soc., 80, 1313 (1958).

[132] Gray, P., Chemistry of free radicals containing oxygen.

Part I. Thermochemistry of the alkoxy radicals RO and

dissociation energies of oxygen bonds, Trans. Faraday

Soc., 52, 344 (1956). [133] Barrow, R. F., Johns, J. W. C., and Smith, F. J., Spectroscopic and thermodynamic properties of gaseous aluminum

monofluoride, Trans. Faraday Soc., 52, 913 (1956). [134] Pedley, J. B., Heats of formation and bond angles of molecules and radicals. II. Hydrocarbon radicals, Trans. Faraday Soc., 58, 23 (1962).

[135] Mackle, H., and McClean, R. T. B., Studies in the thermochemistry of organic sulphides. Part IV. Heat of formation

of the mercaptyl radical, Trans. Faraday Soc., 58, 895

(1962). [136] Bulewicz, E. M., and Sugden, T. M., Determination of the

dissociation constants and heats of formation of molecules

by flame photometry. Part II. Heat of formation of gaseous cuprous hydride, Trans. Faraday Soc., 52, 1475 (1956). [137] Mackle, H., and Mayrick, R. G., Studies in the thermochemistry of organic sulphides. Part I. The gas-phase

heats of formation of phenyl methyl, phenyl ethyl, benzyl

methyl and benzyl ethyl sulphides, Trans. Faraday Soc., 58, 33 (1962). [138] Pritchard, G. O., Pritchard, H. O., Schiff, H. I., and

Trotman-Dickenson, A. F., The reactions of triluoromethyl

radicals, Trans. Faraday Soc., 52 , 849 (1956). [139] Buckley, E., and Whittle, E., Photobromination of methanol.

Part III. Kinetics in the presence of added carbon dioxide, Trans. Faraday Soc., 58, 536 (1962). [140] Barrow, R. F., Dissociation energies of the gaseous monohalides of boron, aluminum, gallium, indium and thallium,

Trans, Faraday Soc., 56 , 952 (1960). [141] Goldhnger, P., and Martens, G., Elementary rate constants

in atomic chlorination reactions. Part III. Bond dissociation energies and entropies of the activated state, Trans. Faraday Soc., 57, 2220 (1961). [142] Busfield, W. K., Ivin, K. J., Mackle, H., and O’Hare, P. A., Studies in the thermochemistry of sulphones. Part IV Gaseous heats of formation of six sulphones and the radical CH3 SO2 , carbon-sulphur dissociation energies in sulphones

and alkane sulphonyl radicals, Trans. Faraday Soc., 57,

1064 (1961). [143] Phillips, L. F., and Sugden, T. M., Determination of dis- sociation constants and heats of formation of molecules

by flame photometry. Part VII. Flame photometric study

of the IO Radical, Trans. Faraday Soc., 57, 914 (1961). [144] Chandrasekharaiah, M. S., Dissociation of energies of alkaline earth oxides, J. Phys. Chem., 68 , 2020 (1964).

[145] Cater, E. D., Lee, T. E., Johnson, E. W., Rauh, E. G., and

Eick, H. A., Vaporization, thermodynamics, and dissociation energy of lanthanum monosulfide, J. Phys. Chem.,

69, 2684 (1965). [146] Singh R. B., and Rai, D. K., Potential curves and bond

strength of PO, J. Phys. Chem., 69, 3461 (1965).

[147] Dillard, J. G., and Kiser, R. W., Ionization and dissociation of ruthenium and osmium tetroxides, J. Phys. Chem.,

69, 3893 (1965). [148] Cubicciotti, D., and Withers, G. L., The enthalpv of formation and the dissociation energy of thallium monofluoride,

J. Phys. Chem., 69, 4030 (1965). [149] Malone, T. J., and McGee, H. A., Jr., Mass spectrometric

investigations of the synthesis, stability, and energetics

of the low-temperature oxygen fluorides. I. Dioxygen di- fluoride, J. Phys. Chem., 69, 4338 (1965). [150] Amphlett, J. C., Coomber, J. W., and Whittle, E., The C—

bond dissociation energy in fluoroform, J. Phys. Chem.,

70, 593 (1966). [151] Kent, R. A., McDonald, J. D., and Margrave, J. L., Mass

spectrometric studies at high temperatures. IX. The sublimation pressure of copper (II) fluoride, J. Phys. Chem.,

70, 874 (1966). [152] Malone, T. J., and McGee, H. A., Jr., ionization potentials of the dioxygen fluoride free radical and the dioxygen di- fluoride molecule, J. Phys. Chem., 70, 316 (1966). [153] Saalfeld, F. E., and Svec, H. J., Mass spectra of volatile hydrides. IV. Silylgermane, J. Phys. Chem., 70, 1753

(1966). [154] Carter, H. V., Chappell, E. I., and Warhurst, E., The

pyrolysis of organomercury compounds, J. Chem. Soc. (London) 106, 1956). [I55J Fettis, G. C., and Trotman-Dickenson, A. F., The reactions

of methyl and ethyl radicals with hydrogen bromide and

the strength of C—H Bonds, J. Chem. Soc. (London)

1961, 3037.

[156] Kerr, J. A., Sekhar-, R. C., and Trotman-Dickenson, A. F., The pyrolyses of hydrazines and benzylamines. C—C and

N—N bond dissociation energies, J. Chem. Soc. (London)

3217, (1963). [157] Grzechowiak, J., Kerr, J. A., and Trotman-Dickenson, A. F., Reactions of difluoroamino-radicals. Part I. Hydrogen

abstraction from acetone and the strength of the C—

Bond in acetone, J. Chem. Soc. (London) 5080, (1965). [158] Somayajulu, G. R., Dissociation energies of diatomic molecules, J. Chem. Phys., 34, 1449 (1961). [159] Porter, R. F., Stabilities of gaseous molecules in the Pb-Se

and Pb-Te systems, J. Chem. Phys., 34, 583 (1961). [160] Curran, R. K. Low-energy process for F

_ formation in SFe, J. Chem. Phys., 34, 1069 (1961). [161] Kennedy, A., and Colburn, C. B., Strength of the N—

bonds in NF3 and of N—F and N—N bonds in N2F4 , J. Chem. Phys., 35, 1892 (1961). [162] Berkowitz, J., Heat of formation of the CN radical, J. Chem. Phys., 36, 2533 (1962). [163] Scheer, M. D., and Fine, J., Entropies, heats of sublimation,

and dissociation energies of the cesium halides, J. Chem.

Phys., 36, 1647 (1962). [164] Tsang, W., Bauer, S. H., and Cowperthwaite, M., Dissociation energy and rate of decomposition of C2 N2 , J. Chem.

Phys., 36, 1768 (1962). [165] Gingerich, K. A., Mass-spectrometric study of the equi- librium between diatomic and monoatomic phosphorus

and dissociation energy of P2 , J. Chem. Phys., 44, 1717

(1966). [166] Hildenbrand, D. L., and Murad, E., Mass-spectrometric

determination of the dissociation energy of beryllium monofluoride, J. Chem. Phys., 44, 1524 (1966). [167] Yates, R. E., Blauer, J. A., Greenbaum, M. A., and Farber,

M., Dissociation energy of F2(g) obtained from the study of gas flow of intermediate pressures through an orifice, J. Chem. Phys., 44, 498 (1966). [168] Cater, E. D., Rauh, E. G., and Thorn, R. J., Uranium monosulfide. III. Thermochemistry, partial pressures, and dis- sociation energies of US and US2 , J. Chem. Phvs., 44,

3106 (1966). [169] DeMaria, G., Ginerich, K. A., Malaspina, L., and Piacente,

V., Dissociation energy of the gaseous A1P molecule, J. Chem. Phys., 44 , 2531 (1966). [170] Murad, E., Hildenbrand, D. L., and Main, R. R., Dissociation energies of group III A monofluorides—The possibility of potential maxima in their excited II states, J. Chem.

Phys., 45 , 263 (1966).

357-055 0 - 70 -2 5
[171] Zmbov, K. F., and Margrave, J. L., Mass-spectrometric

studies at high temperatures. XI. The sublimation pres- sure of NdF3 and the stabilities of gaseous NdF2 and NdF,

J. Chem. Phys., 45, 3167 (1966). [172] Sandoval, A. A., Moser, H. C., and Kiser, R. W., Ionization and dissociation processes in phosphorus trichloride and

diphosphorus tetrachloride, J. Phys. Chem., 67, 124 (1963). [173] Ackermann, R. J., Rauh, E. G., Thorn, R. J., and Cannon,

M. C., A thermodynamic study of the thorium-oxygen sys- tem at high temperatures, J. Phys. Chem., 67 , 762 (1963).

[174] Blue, G. D., Green, J. W., Bautista, R. G., and Margrave,

J. L., The sublimation pressure of calcium(II) fluoride and

the dissociation energy of calcium(I) fluoride, J. Phys.

Chem., 67 , 877 (1963). [175] Pritchard, G. O., and Thommarson, R. L., The C—H bond

dissociation energies in CF3H, C2F5H, and C3F7H, J. Phys.

Chem., 68, 568 (1964). [176] Padley, P. J., and Sugden, T. M., Determination of the

dissociation constants and heats of formation of molecules

by flame photometry, Trans. Faraday Soc., 55, 2054 (1959). [177] Bulewicz, E. M., and Sugden, T. M., Determination of the

dissociation constants and heats of formation of molecules

by flame photometry. Part 5. —The stabilities of MgO and

MgOH, Trans. Faraday Soc., 55 , 720 (1959). [178] Witt, W. P., and Barrow, R. F., The heat of sublimation

of aluminum trifluoride and the heat of formation of aluminum monofluoride, Trans. Faraday Soc., 55 , 730 (1959).

[179] Reed, R. I., and Snedden, W., Studies in electron impact

methods. Part 6. — The formation of the methine and carbon

ions, Trans. Faraday Soc., 55, 876 (1959). [180] Drowart, J., Colin, R., and Exsteen, G., Mass-spectrometric

study of the vaporization of lead monoxide, Trans. Faraday

Soc., 61, 1376 (1965). [181] Colin, R., Drowart, J., and Verhaegen, G., Mass-spectrometric study of the vaporization of tin oxides dissociation energy of SnO, Trans. Faraday Soc., 61, 1364 (1965).

[182] Johnston, H. S., and Bertin, H. J., Jr., Heat of formation of

nitrosyl fluoride, J. Am. Chem. Soc., 81, 6402 (1959). [183] Cotton, F. A., and Monchamp, R. R., The heat of sublimation and the metal-metal bond energy in Mn2(CO)io, J- Chem. Soc. (London) 533 (1960). [184] DeMaria, G., Goldfinger, P., Malaspina, L., and Piacente,

V., Mass-spectrometric study of gaseous molecules ZnS,

ZnSe and ZnTe, Trans. Faraday Soc., 61, 2146 (1965). [185] Corbett,!5

., Tarr, A. TVI., and Whittle, E., Vapour-phase

bromination of fluoroform and methane, Trans. Faraday

Soc., 59, 1609 (1963). [186] Bautista, R. G., and Margrave, J. L., The heat of sublimation of calcium chloride, J. Phys. Chem., 67, 2411 (1963). [187] Bidinosti, D. R., and McIntyre, N. S., The metal-metal

bond dissociation energy in cobalt octacarbonyl, Chem.

Comm. 1, (1967).

[188] Ferreira, R., Principle of Electronegativity Equalization. Part 2. -Bond-dissociation energies, Trans. Faraday Soc., 59, 1075 (1963). [189] Colin, R., Goldfinger, P., and Jeunehomme, M., Massspectrometric studies of the vaporization of the sulphides

of calcium, strontium, and barium. The dissociation energy

of S2 and SO, Trans. Faraday Soc., 60, 306 (1964). [190] Drowart, J., Exsteen, G., and Verhaegen, G., Mass-spectrometric determination of the dissociation energy of the molecules MgO, CaO, SrO, and Sr2 0, Trans. Faraday

Soc., 60, 1920 (1964).

[191] Sugden, T. M., and Schofield, K., Heats of dissociation of gaseous alkali earth dihydroxides, Trans. Faraday Soc., 62 , 566 (1966). [192] Jensen, D. E., and Padley, P. J., Dissociation energies of the alkali metal hydroxides, Trans. Faraday Soc., 62,

2132 (1966). [193] Coomber, J. W., and Whittle, E., Bromination of fluoro- alkanes. Part 3. — Methane, Fluoroform and Fluoro- Ethanes, Trans. Faraday Soc., 62, 1553 (1966). [194] McEwan, M. J., and Phillips, L. F., Dissociation Energy

of Na02 , Trans. Faraday Soc., 62, 1717 (1966). [195] Hunter, G., Adiabatic dissociation energies for the ground

states of the H2 , HD, and D2 molecules, J. Chem. Phys.,

45 , 3022 (1966).

[196] Bulewicz, E. M., and Sugden, T. M., Determination of the dissociation constants and heats of formation of molecules

by flame photometry. Part 4. — The Stability of GaOH,

InOH and T1H, Trans. Faraday Soc., 54, 830 (1958). [197] Chupka, W. A., Inghram, M. G., and Porter, R. F., Dis- sociation energy of gaseous LaO, J. Chem. Phys., 24,

792 (1956). [198j Lindeman, E. P., and Gutty, J. C., Determination of the O—O bond energy in hydrogen peroxide by electron impact,

J. Chem. Phys., 29, 247 (1958). [199] DeMaria, G., Burns, R. P., Drowart, J., and Inghram, M.

G., Mass-spectrometric study of gaseous molybdenum,

tungsten and uranium oxides, J. Chem. Phys., 32. 1373

(1960). [200] Reed, R. I., and Snedden, W., The ionization potential of NH, J. Chem. Soc. (London), 4132 (1959). [201] Brewer, L., Somayajulu, G. R., and Brackett, E., Thermodynamic properties of gaseous metal dihalides, Chem.

Rev., 63, 111 (1963). [202] Domalski, E. S., and Armstrong, G. T., The heats of combustion of polytetrafluoroethylene (Teflon) and graphite

in elemental fluorine, J. Res. Nat. Bur. Stand. (US), 71A,

(Phys. and Chem.) No. 2, 105 (1967). [203] Brewer, L., Hicks, W. T., and Krikorian, O. H., Heat of sublimation and dissociation energy of gaseous C>, J. Chem.

Phys., 36, 182 (1962).

6
Table of Bond Dissociation Energies
-

'
Table of Bond Dissociation Energies

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Ag-Ag Ag2 -» 2Ag 171.5 41.0 Effusion; M.S. 1957 95

157.3 37.6 Effusion; M.S. 1956 198

157.3 37.6 Effusion; M.S. 1960 91 163 39 Analysis of data 1956 3

157.3 ±9.2 37.6 ±2.2 Analysis of data 1962 6

171 ±8 41 ±2 Analysis of data 1963 7 156.9 37.5 Thermochemical;

159 ±8 38 ±2 based on 9 1967

Ag-Au AgAu—» Ag + Au 199.2 ±9.2 47.6±2.2 Effusion; M.S. 1960 91

Ag-Br AgBr-^ Ag+ Br 289 69 Thermochemical 1956 3 251.0 60 Thermochemical 1950 4 289 ±42 69 ±10 Thermochemical 1962 6 289 ±42 69 ±10

Ag-Cl AgCl^ Ag + Cl 301 72 Thermochemical 1956 3 299.2 71.5 Thermochemical 1950 4 318 ±21 V 76 ±5 Thermochemical 1962 6 314±21 75 ±5

Ag-Cu AgCu —» Ag + Cu 170.3 40.7 Effusion; M.S. 1960 91

170.3 ±9.2 40.7 ± 2.2 174.1 41.6 Effusion; M.S.

170.3 40.7 Thermochemical; 1967 172 ±8 41 ± 2 based on 9

Ag-H AgH-^ Ag+H 243 58 Analysis of data 1956 3 241.0 57.6 Thermochemical 1950 4 222 ±8 53 ±2 Extrapolation of X'S 1962 6 230 ± 1

55 ± 3 levels

Ag-I AgI-> Ag+I 287.4 68.7 Convergence in B state 1950 4

Ag-0 AgO —* Ag + O 238 ±42 57 ± 10 L.B.S. for ground state 1962 6

134 ±38 32 ±9 L.B.S. for B22 state 1953 1

Ag-Sn AgSn —» Ag+ Sn 132.2 ±21 31.6±5 Effusion; M.S. 1960 63

Al-Al A12 -»2A1 188 ±42 45 ±10 M.S. 1962 6 163 39 167 40 Thermochemical; 1967 based on 9

*Throughout the table in the Methods, remarks column,

E. I. — Electron Impact; A. P. — Appearance Potential.

the following abbreviations have been used: M.S.-Mass Spectrometer; L.B.S.- Linear Birge-Sponer Extrapolation:

9
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Al-Br AlBr A1 + Br 439 105 Analysis of data 1960 140 439 105 443 106 Thermochemical; 1967 105 ±2 based on 9

Al-Cl A1C1-* Al + Cl 490 117 Analysis of data 1960 140

492.0 117.6 495.8 118.5 Thermochemical; 1967

490 ±13 117±3 494 ±13 118 ± 3 based on 9

AlCl 2 -» A1C1 + C1 391.2 ±21 93.5 ±5 393.3 94.0 Thermochemical 1962 6 406 97 400 ±8 95.5 ±2 402 ±8 96 ±2

A1C13 ^ aici 2 + ci 397 ±21 95 ±5 400 95.5 Thermochemical 1962 6

372 89 Thermochemical; 1967

372 ±8 89 ±2 3 72 ±8 89 ±2 based on 9

OA1C1-* A10 + Cl 552 132 Thermochemical; 1967 based on 9 515 ±84 123 ±20 Thermochemical 1962 6

Al-F AIF^ Al + F 653 156 Analysis of data 1960 140

653.1 ± 7.5 156.1 ±1.8 Equilibrium pressure; 1959 178 A1F3 (C) + 2 A1 = 3A1F(S)

661 158 Thermochemical 1956 133 649 155 Thermochemical 1957 95

665 ±13 159 ±3 Effusion; M.S. 1966 170 661 ±8 158 ±2 Effusion; M.S. 1963 174 654.8 ±8 156.5 ±2 A1F3 + 2A1 = 3A1F 1962 6

659.0 157.5 663.3 158.6 Thermochemical; 1967 659.0±6.2 157.5 ±1.5 663.6 ±6.2 158. 6± 1.5 based on 9

A1F2 —> A1F + F 546.0 ±42 130.5 ±10 Thermochemical 1962 6

A1F3 —» A1F2 + F 544 ± 46 130 ± 11 Thermochemical 1962 6

OA1F -4 A10 + F 674 ±84 161 ±20 Thermochemical 1962 6

761 182 Thermochemical; 1967 761 ±42 182 ± 10 based on 9

Al-H A1H^A1 + H <295 < 70.5 Predissociation 1950 4 280.7 ±5.0 67.1 ±1.2 Spectroscopic; predis- 1961 53

sociation 280 ±21 67 ±5 Thermochemical 1962 6 280 67 284.9 68.1 Thermochemical; 1967 280.3 ±6.3 67.0 ±1.5 284.9 ±6.3 68.1 ±1.5 based on 9

10
Tabic of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mo-l kcal/mol kj/mol kcal/mol

Al-I All —» A1 +

364.0 87.0 Analysis of fluctuation 1960 140 bands

364 ± 13 87 ±3 Analysis of data 1962 6 364 87 367.7 87.9 Thermochemical; 1967 364 ±4 87 ± 1 368 ±4 88 ±1 based on 9

Al-0 A10 — A1 + 0 481 ±21 115 ±5 Effusion; M.S. 1960 104 369 136 Flame photometry 1958 16 481 ±21 1 15 ± 5 Thermochemical 1962 6

479.5 114.6 484.5 115.8 Thermochemical; 1967 481 ±8 1 15 ±2 485 ±8 1 16±2 based on 9

OA1F —» A1F + 0 582 139 Thermochemical; 1967 based on 9 0A1C1—» A1C1 + 0 540 129 Thermochemical; 1967 540 ±41 129± 10 based on 9

Al-P AlP^ Al + P 212.6 ±13 50.8 ±3 Effusion; M.S. 1966 169

Al-S A1S —» A1 + S 339 ±67 81 ±16 Spectroscopic; L.B.S. 1959 54

326 ±21 78 ±5 Spectroscopic; predis- 1962 6

sociation 402 96 406 97 Thermochemical;

based on 9

1967

As-As As2 * 2 As 379.9 ±21 90.8 ±5 Spectroscopic; predis- 1962 6

sociation 379.9 90.8 382.8 91.5 Thermochemical; 1967 380 ±21 91 ± 5 382.8 ±21 91.5 ± 5 based on 9

As-Cl AsC13 —» AsC12 + Cl 444 106 448 107 Thermochemical; 1967 based on 9

As-N AsN —

As + N 628 ±126 150 ±30 L.B.S. 1962 6 577 138 582 139 Thermochemical; 1967 based on 9

As-0 AsO —» As + 0 473 ±8 113±2 477 114 Spectroscopic; predis- 1960 6

sociation 477.4 114.1 481.6 115.1 Thermochemical; 1967 477 ±8 114±2 481 1 15 ± 2 based on 9

At-At At2 —» 2At 115.9 27.7 Theoretical 1960 109

11
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Au-Au Au2 —> 2Au 210.5 50.3 Thermochemical; M.S. 1956 108

221.8 53.0 Effusion: M.S. 1957 95

215.5 51.5 Effusion; M.S. 1960 91 215.1 51.4 217 51.9 Thermochemical; 1967 215.5±6.3 51.5 ± 1.5 218±6 52 ± 1.5 based on 9

Au—Cl AuCl —* Au + Cl 293 ±59 70 ±14 Spectroscopic; L.B.S. 1962 6 289 69 293 70 Thermochemical; 1967 289 ±63 69 ±15 293 ±63 70± 15 based on 9

Au—Cr AuCr—» Au + Cr 210.9± 14.6 50.4 ±3.5 M.S. 1962 62 213 51 Thermochemical: 1967 211.3 ±6.3 50.5± 1.5 based on 9

Au-Cu AuCu —> Au + Cu 228.0 ±9.2 54.5± 2.2 Effusion: M.S. 1960 91

Au-H AuH^ Au + H 297 ±10 71 ±2.5 Spectroscopic 1962 6 285.3 68.2 289.1 69.1 Thermochemical; 1967 285 ±13 68 ±3 289 ±13 69 ±3 based on 9

Au-Pd AuPd—» Au + Pd 139.3 ±21 33.3 ±5 M.S. 1962 62

Au-Sn AuSn —» Au + Sn 240.6 ±17 57.5 ±4 Effusion; M.S. 1962 63

B-B Bo -> 2B 274.1 65.5 M.S. 1962 58

260.7 62.3 M.S. 1962 6 293 70 297 71 Thermochemical; 1967 293 ±21 70 ± 5 297 ±21 71 ± 5 based on 9

B2 C14 -> 2BC1> 331 79 Calorimetry 1959 102 246.0 58.8 Thermochemical 1962 6

BoF4 -* 2BF> 151 36 Thermochemical 1962 6

BoO, -* 2BO >416.7 >99.6 Effusion: M.S. 1956 90 498 ±84 119 ±20 502 120 Thermochemical 1962 6 502 120 506 121 Thermochemical: 1967 502 ±84 120 ± 20 506 ±84 121 ±20 based on 9

B-Br BBr^ B + Br 431 103 Analysis of data 1960 140

433.0 ±8 103.5 ±2 436.8 104.4 Analysis of data 1962 6 433.0 103.5 436.4 104.3 Thermochemical; 1967

433.0 ±21 103.5 ±5 435 ±21 104 ± 5 based on 9

12
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

B-C BC^B+C 444 106 Thermochemical; 1967 based on 9

B-Cl BC1—> B + Cl 531 127 Analysis of data 1960 140 494 ±42 1 1 8 ± 10 498 119 Spectroscopic; extrapola- 1962 6

tion 531 127 536 128 Thermochemical; 1967 531 ±29 127 ± 7 536 ±29 128 ± 7 based on 9

OBCW BO+C1 515 ±75 123 ± 18 Thermochemical 1962 6 460 110 Thermochemical; 1967

460 ±42 110±10 based on 9

B-F BF^B + F 774 185 Analysis of data 1960 140

774 ±63 185 ±15 778 186 Spectroscopic 1962 6

753 ±13 180 ±3 Effusion; M.S. 1966 170 757±17 181 ± 4 M.S.; B(c)+CaF2 (c) 1965 69 = BF(g)+ CaF(g)

759.8 181.6 764.0 182.6 Thermochemical; 1967 759.4 ± 10.5 181.5 ± 2.5 766 ±13 183 ±3 based on 9

BF2 ^BF + F 565 ±105 135 ±25 569 136 Thermochemical 1962 6 515 123 M.S.; B(c) + CaF>(c) 1965 69 523 ±63 125 ± 15 = BF(g) + CaF(g)

BF:! -*BF2 ;F 557 ±84 133 ±20 561 134 Thermochemical 1962 6 665 159 M.S.; B(c) + CaF2 <c) 1965 69 = BF(g) + CaF(g)

FBO —Bo + F 820 ±113 196 ±27 824 197 Thermochemical 1962 6

711 170 Thermochemieal; 1967 711 ±42 1 70 ± 10 based on 9

B-H BH— B + H 289 ±38 69 ±9 Spectroscopic 1953 1 327.2 78.2 ±1 Predissociation 1962 6 327.2 78.2 331.0 79.1 Thermochemical; 1967 326 ±4 78 ±1 based on 9

B-N BN —

B + N 385 ± 50 92 ±12 L.B.S. for ground and 1962 6

:, n states 385 92 389 93 Thermochemical; 1967 385 ±21 92 ±5 389±21 93 ±5 based on 9

357-055 0 - 70 -3 13
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

B-O BO— B + 0 715 171 L.B.S. for X2 2, A2 I1, B

22, 1960 50 c2 n.

770 ±46 184 ± 11 774 185 1959 51 782 187 787 188 Thermochemical; 1967

782 ±42 187 ± 10 787 ±42 188± 10 based on 9

ClBO^BCl+O 791 ± 75 189 ±18 Thermochemical 1962 6

711 170 Thermochemical; 1967

171 ± 10 based on 9

FBO-* BF+ 0 816±117 195 ±28 820 196 Thermochemical 1962 6 732 175 Thermochemical; 1967

732 ±42 175 ± 10 based on 9

B-S BS-^B + S 577±117 138 ±28 582 139 Spectroscopic 1962 6 494 118 498 119 Thermochemical; 1967

494 ±42 1 18 ± 10 498 ±42 119 ± 10 based on 9

B-Si BSi—» B± Si 285 68 Thermochemical; 1967

based on 9

Ba-Br BaBr —» Ba + Br 269.9 ±54 64.5 ± 13 274.1 65.5 Spectroscopic; L.B.S. for 1962 4; 6 ground state Thi 5 value is proba bly too low (see 11)

BaBr2 —* BaBr+ Br 598 ±54 143 ±13 Thermochemical 1962 6

If D\ is t to low (see abo\ e); this value is too high

Ba-Cl BaCl —» Ba + Cl 259 ±50 62 ±12 264 63 Spectroscopic; L.B.S. for 1962 4; 6 ground state 494 ±21 118 ± 5 Flame photometry; 1964 11 h2 + o2 +n2 477 ±25 114 ±6 Flame photometry; 1965 23 494 1 18 ± 10 H2 + 02 + N2

BaCl2 —* BaCl + Cl 728 ±50 174 ± 12 Thermochemical 1962 6

201 gives Dx F D2 — 236 Kcal mol* 1

; D2 is pn •bably about

23f — 118± 10= 11 3± 10 Kcal mol - 1 431 ±42 103 ±10 Flame photometry; 1965 23 456 ±42 109 ± 10 h, + o2 +n2 14
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Ba-F BaF —» Ba + F 364 ± 71 87 ±17 368 88 Spectroscopic; 1962 4; 6 L.B.S. for ground state. 561 ±8 134 ±2 Effusion; M.S.; 1964 68 2BaF = Ba + BaF2 552 ±17 132 ±4 Effusion; M.S.; 1964 68

Ba + A1F = A1 + BaF

602 ±29 144 ±7 Flame photometry; 1964; 11; 569 ±42 136 ± 10 h2 +o2 +n2 1965 23

BaF2 ^ BaF + F 799 ±71 191 ±17 Thermochemical 1962 6

584.1 ±25 139.6 ±6 Effusion; M.S. 1964 68

201 gives + Dz = 219 Kcal n ml -1

; 68 gives ^ 73, and 6 gives

279 Kcal n ol" 1 - 569 ±42 136 ±10 Flame photometry; 1964 11 586 ±42 140± 10 h2 + o2 + n2

Ba-H BaH —> Ba + H 172 ±8 41 ±2 1 76 42 Spectroscopic; pre- 1962 1; 6

dissociation of C2 2

195.5 46.73 Spectroscopic; 1966 25; predissociation 1965 24;26

197.3 47.16 Spectroscopic; Rydberg 1966 25; extrapolation 1965 24;26

Ba-0 BaO—> Ba + 0 482.4 ±9.6 115.3 ± 2.3 Flame photometry; 1965 71 CO-Air; Band & Line

Intensity

539 ±14.6 128.7 ±3.5 Thermochemical 1951 12 544 ±21 130 ±5 Effusion; M.S. 1955 13 573 ±8 137 ±2 577 138 M.S. 1962 6 590 ±42 141 ±10 Thermochemical 1964 144

545.6 ±25 130.4 ±6 M.S.; Ba + SO = BaO + S 1964 189 577 ±21 138± 5 Flame photometry H2 + 02 1966 191 567.4 ±21 135.6 ±5 Thermochemical 1964 14 561 ±21 134 ±5 Recalculated from earlier 1965 22 561 ±42 134 ± 10 data BaOH^Ba + OH 448 107 Effusion; M.S.; 2BaO 1964 14 + HOH = BaOH + O. 464 ±33 111 ±8 Flame photometry; 1965 22 h2 +o2 +n2 477 114 Flame photometry; 1965 48

473 ±42 1 13 ± 10 H2 + 02 + n2

Ba(OFI)2 ^BaOH 414 99 Effusion; M.S. 1964 14 + OH

Ref. 191 giv bs D\ + D> = 229 ± 12 Kcal mol" 14 gives

D\ + Di = 206 Kcal mol +l. 510±50 122 ±12 Based on D> = 107; 191 460 ±84 1 10 ± 20 D, + D2 = 229 ±12 14

15
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Ba-S BaS —

Ba + S 396.2 ± 18.8 94.7 ±4.5 Effusion; M.S. 1964 189

Be-Cl BeCl—» Be + Cl 460 ±63 110 ± 15 464 111 Spectroscopic; ex- 1962 6

trapolation of X2 Z and

A2n. 385 92 389 93 Thermochemical; 1967 385 ±63 92 ±15 389±63 93 ±15 based on 9

BeCl 2 -»BeCl + Cl 456 ± 63 109 ±15 460 110 Thermochemical 1962 6

539.7 129.0 Thermochemical: 1967

536 ±63 128 ± 15 540 ±63 129 ±15 based on 9

Be-F BeF —» Be + F 669 ±84 160 ±20 674 161 Spectroscopic; 1962 6

extrapolation of X21

and Affl. < 656.1 < 156.8 M.S.; Be±BeF> = 2BeF 1965 73 < 617.6 < 147.6 M.S.; Al + BeF2 = BeF 1965 73 + A1F

564.4 ± 9.6 134.9 ±2.3 M.S. 1966 166

575.3 137.5 579.1 138.4 Thermochemical: 1967 573 ±42 137 ± 10 577±42 138 ± 10 based on 9

BeF>—» BeF + F 586 ±84 140 ±20 590 141 Thermoehemical 1962 6

698.7 167.0 Thermochemical; 1967 690 ±63 165 ± 15 699± 63 167 ±15 based on 9

Be-H BeH—> Be + H 222 ± 29 53 ±7 226 54 Spectroscopic; extrapola- 1962 6

tion of X2 X and A2 FI 222 53 226 54 Thermochemical: 1967 222 ±21 53 ± 5 226±21 54±5 based on 9

Be-0 BeO—» Be + O 445.2 ± 12.6 106.4 ±3 449.4 107.4 M.S. 1962 6 443.9 ± 9.6 106.1 ±2.3 Spectroscopic 1964 86 448 107 Thermochemical: 1967 444 ±21 106 ± 5 448±21 107 ± 5 based on 9

Bi-Bi Bi-i —* 2Bi 197 ±4 47 ±1 201 48 Thermochemical; AH vap. 1962 6

192.5 46.0 194.6 46.5 Thermochemical: 1967 192 ±4 46 ±1 197 ±4 47 + 1 based on 9

Bi-S BiS^ Bi + S 305 73 Thermochemcial; 1967 based on 9

16
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/roiol kcal/mol kj/mol kcal/mol

Bi-Se BiSe —=

*

Bi + Se 231.4 55.3 Effusion; M.S. 1960 61 259 61.8 Thermochemical; 1967 based on 9

Bi-Te BiTe —> Bi + Te 202.5 48.4 Effusion; M.S. 1960 61 225 53.7 Thermochemical; 1967

based on 9

Br-Br Br2 ~* 2Br 190.08 ±.12 45.43 ±0.03 192.9 46.1 Spectroscopic; con- 1962 6 vergence of bands

190.18 45.455 192.86 46.095 Thermochemical; 1967 190.16 ±.04 45.45 ±0.01 192.88 46.10 ±0.01 based on 9 ±0.04

Br-Cl BrCl—» Br + Cl 215.30 ±0.25 51.458 ±0.06 218.4 52.2 Thermochemical 1962 6

215.85 51.59 218.91 52.32 Thermochemical; 1967 21 5.9 ±0.4 51.6 ±0.1 21 8.8 ±0.4 52.3 ±0.1 based on 9

Br-F BrF —» Br + F 230.04 ±0.25 54.98 ±0.06 233.5 55.8 Spectroscopic; converg- 1962 6 ence of bands

281.2 67.2 284.9 68.1 Thermochemical; 1967

based on 9

Br-H HBr-^H + Br 362.71 ±0.54 86.69 ±0.13 366.5 87.6 Thermochemical 1962 6 361.5 86.4 Theoretical 1963 178 362.50 86.64 366.27 87.54 Thermochemical; 1967 362.3 ±0.4 86.6 ±0.1 366.1 ±0.4 87.5 ±0.1 based on 9

Br-0 BrO^Br+O 231.0 55.2 Spectroscopic 1958 33

231.4 ±2.5 55.3 ±0.6 235.1 56.2 Spectroscopic; extrapola- 1962 6

tion of A2 FI. 231.25 55.27 235.27 56.23 Thermochemical: 1967

231.4 ±0.4 55.3 ±0.1 235.1 56.2 ±0.1 based on 9

C-Br CH3 Br —» CH3 + Br 224.7 53.7 E.I.; M.S. 1959 179 280 67 ( T= 1000 K) pyrolysis 1962 6 293 70 Analysis of data 1966 8 279.9 66.9 285.8 68.3 Thermochemical; 1967 280 ±8 67 ± 2 285 ±8 68 ±2 based on 9

CH2Br2 -* CH2 Br + Br 249.8 ±14.6 59.7 ±3.5 E.I.; M.S. 1959 179

261.5 62.5 (at 950 K) Pyrolysis 1962 6 255 ±13 61 ± 3

17
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

CHBr3 -»CHBr2 + Br 257.7 ±17 61.6 ± 4 E.I.; M.S. 1959 179

232.2 55.5 Pyrolysis 1962 6

CBr4 —* CBr3 + Br 207.9 49.7 E.I.; M.S. 1959 179

205 49 (at 750 K) Pyrolysis 1962 6 205 49 209 50 Thermochemical; 1967

205 ±13 49 ±3 209 ±13 50 ± 3 based on 9

CCl3 Br—> CC13 + Br 207.1 ±12.6 49.5 ±3 ( T= 400-500 K); E.I.; 1962 6 M.S.

205 49 (T = 800 K), pyrolysis 1962

230.5 ±5.0 55.1 ±1.2 Recalculation of earlier 1965 70

data on photobromination.

226 ±8 54 ±2 Analysis of data 1966 8 213 51 218 52 Thermochemical; 1967

213 ±13 51 ± 3 218±13 52 ±3 based on 9

CF3 Br —

CF.t + Br 272 65 (T= 1050 K), pyrolysis 1962 6 290.4 ±3.3 69.4 ±0.8 Equilibrium Br2 + CF3 H 1967 15 = HBr+CF3 Br

276 66 276 66 Thermochemical; 1967 285 ±13 68 ±3 based on 9

BrCN—> CN+Br 377 90 380 91 Thermochemical; 1967 based on 9

C-C C2 -* 2C 599.1 ±13 143.2 ±3 603.3 144.2 M.S. 1962 6

602 ±21 144 ±5 Spectroscopic 1962 203

602 ±21 144 ±5 607 ±21 145 ±5

CH3 CN -* CH3 + CN 431 103 (

= 400-500 K); E.I. 1962 6

431 103 A.P.; M.S. 1959 179 498 119 506 121 Thermochemical; 1967

498 ±21 1 19 ± 5 506 ±21 121 ±5 based on 9

CH2 FCN-»CH2 F - 460 -110 (T = 400-500 K); E.I.; 1960 16 + CN M.S.

chf2 cn-*chf2 485 116 (T =400-500 K); E.I.; 1960 16 + CN M.S.

cf3 cn-*cf3 +cn 502 120 (T= 400-500 K); E.I.; 1960 16 M.S.

18
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

C2 N2 —* 2CN 435 104 A.P.; M.S. 1961 127 607 145 Shock wave; thermo- 1961 120 chemical

523 ±33 125 ±8 (T = 1700-2500 K) 1962 164 Shock wave

607 145 Analysis of data 1966 8 598 143 602 144 Thermochemical; 1967 598 ±21 143 ±5 603 ±21 144 ±5 based on 9

ch2 co-+ ch2 +co 337.2 80.6 342.7 81.9 Thermochemical; 1967

based on 9

CHsCO^ CH3 + CO 44.4 10.6 Analysis of data 1966 8

47.3 11.3 Thermochemical; 1967 46 ± 4 1

1

± 1 based on 9

C-Cl CC1^C + C1 322 77 Spectroscopic; L. B. S. 1961 17

• for ground state. 335 ±42 80 ±10 338.1 80.8 Analysis of data 1961 6

CC14 ^CC13 +C1 284.1 ±13 67.9 ±3 A.P.; M.S. 1956 124 301 ±10 72 ±2.5 A.P.; M.S. 1958 18 337.2 80.6 Based on rate constants; 1961 141 previous data. 318 76 A.P.; M.S. 1961 19 311.7 ±8 74.5 ±2 Thermochemical analysis 1965 70

of earlier data on

photobromination.

305 ±8 73±2 Analysis of data; 1966 8 thermochemical.

280 67 285 68 Thermochemical; 1967 293 ±21 70±5 based on 9

CF3 C1 —» CF3 + C1 347 ±12 83 ±3 A.P.; M.S. 1956 124 ~ 335 ~ 80 1962 6 335 80 339 81 Thermochemical; 1967 339±13 81 ± 3 based on 9

CHaCl-»CH., + Cl 328 78.4 A.P.; M.S. 1959 179

336.8 80.5 ( T= 400-500 K); E.I.; 1962 6 M.S. 318 76 Based on rate constants; 1961 141 previous data

351 ±8 84 ± 2 Analysis of data; 1966 8 thermochemical

335.1 80.1 341.4 81.6 Thermochemical; 1967 339 ±21 81 ± 5 based on 9

19
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

CH2 C12 -^CH2 C1+C1 307.9 ±11.

73.6 ±2.8 (

= 400-500 K); A.P.; 1959 179 M.S. 314 ±75 Based on rate constants; 1961 141 previous data

ch2 ci ->ch2 +ci 318.4 ±13 76.1±3 A.P.; M. S. (Based on 1959 179 Z)(CH—H)= 119.9 Kcal mol -1

)- 498 119 Recalculated; based on 1967

D(CH—H) = 99.3 Kcal

mol -1 -

C1CN —* CN + Cl 435 104 439 105 Thermochemical; 1967

based on 9

C0C1-»C0 + C1 26.4 6.3 Based on rate constants; 1961 141 previous data

C0C12 ^C0C1 + C1 328.4 78.5 Based on rate con- 1961 141

tants; previous data.

C-F CC13F-»CC13 + F 427 ±29 102 ±7 (7=400-500 K); E.I.; 1962 6 M.S. 448 ±11.7 107 ±2.8 Recalculation of earlier 1965 70

data on photobromination

444 ±13 106 ±3 Analysis of data 1966 8 410 98 414 99 Thermochemical; 1967 444 ±21 106 ±5 based on 9

cf4 ^cf3 + f 506 ±10.5 121 ±2.5 E.I.; M.S. 1958 18 506 ±17 121+4 E.I.; M.S. 1962 6

523 125 527 126 Thermochemical; 1967

based on 9

532.6 127.3 Thermochemical; 1967 523 ±17 125 ±4 based on 202

ch3f-* ch3 + f 494 118 Analysis of data 1962 6 452 ±13 108 ±3 Thermocbemical 1966 8 452 ±21 108 ± 5

:-h CH-» C + H 335 ±4 80 ±1 Spectroscopic; 1956 3

predissociation 318.4 76.1 Theoretical 1962 134 335 ±21 80 ±5 Spectroscopic; 1964 79

2 11 emission

334.7 80.0 338.9 81.0 Thermochemical; 1967 339 ±2.1 81 ±0.5 based on 9

20
Table of Bond Dissociation Energies — Comtinued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

CH2 ^CH + H 502 120 A.P.; M.S. 1959 179

436.4 104.3 Theoretical 1962 134 536 ±25 128 ± 6 Analysis of data 1962 6 < 405.0 ±9.6 < 96.8 ±2.3 Recalculation of 1963 67

earlier M.S. data 452 ±25 108 ±6 Analysis of data 1966 8

415.5 99.3 421.7 100.8 Thermochemical; 1967 based on 9 and 122.

C H.-j —* C H*2 + H 485 116 Theoretical 1962 134 356 ±29 85±7 Analysis of data 1962 6 <540 < 129 Recalculation of earlier 1963 67 M.S. data 469.86 112.30 Photoionization 1965 122 435 ±25 104±6 Analysis of data 1966 8

466.5 111.5 471.1 112.6 Thermochemical; 1967 469.9 ±0.4 1 12.3 ±0.1 473 ±4 1 13 ± 1 based on 9

ch4 ^ch:! +h 397 95 A.P.; M.S. 1959 179 423 101 Photobromination 1956 3 434.7 103.9 Photohalogenation 1961 155

425.1 ±8 101.6 ±2 431 ±8 103 ±2 Analysis of data 1962 6 423 101 Theoretical 1962 134

425.47 ±0.21 101.69 ±0.05 Photoionization 1965 122 435 ±4 104 ±1 Analysis of data 1966 8

434.3 103.8 1967

425.1 101.6 431.8 103.2 Thermochemical; 1967 101.6 ±2.0 102.7 ± 2.0 based on 9

cd4 ^cd3 ±d 438.99 ±0.2 104.92 ±0.05 Photoionization 1965 123

CBr3 H -* CBr.t + H 389 ±8 93 ±2 (r=400 K); 1962 6 photobromination

377 90 Thermochemical 1962 6 368 ±8 88 ±2 377 ±8 90 ± 2

CH3 Br—» CH2 Bt + H ~414 ~99 Photobromination 1956 3 402 96 Thermochemical 1962 6 406 ±21 97 ±5

cci3 h^cci3 +h 377 ±8 90 ±2 Photobromination 1956 3 389 93 Rate constant data 1961 141 372 ±13 89 ±3 (

T

= 400-500 K); E.I.; 1962 6 M.S. 389 93 (jT=430 K); 1962 6 photochlorination

400.4 ± 6.3 95.7 ±1.5 Recalculation of earlier 1965 70

data on photobromination

372 89 380 91 Thermochemical; 1967 372 ±13 89 ±3 377 ±13 90 ±3 based on 9

357-055 0 - 70 -4 21
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

CH3 CN-+CH2 CN+H <331 <79 A.P.; M.S. HCN—» H + CN 464 ±25 111 ±6 Thermochemical 1956 3 540 ±13 129 ±3 Shock wave; 1961 120 Kr+C2 N2 ; Kr + HCN

540 ±13 129 ±3 Analysis of data 1966 8

531 127 540 129 Thermochemical; 1967 531 ±21 127 ± 5 540±21 129±5 based on 9

HCO—> H + CO 127.2 ±9.6 30.4 ±2.3 (T = 400-500 K); 1962 6

E.I.; M.S.

75 18 Analysis of data 1966 8

119.7 28.6 124.7 29.8 Thermochemical; 1967

\

based on 9

H2 CO-» hco + h <326 <78 Photolysis 1962 6

314 ±8 75 ±2 E.I.; M.S. 1962 6

368 ±8 88 ±2 Analysis of data 1966 8 314 75 318 76 Thermochemical; 1967

based on 9

cf3 h^cf3 +h 431 ±17 103 ±4 E.I.; M.S.; 1956 124 A//^CF3) = -117±2

427 ±8 102 ±2 From CF3 + CH4 —1956 138 CF3 H + CH3 431 ±17 103 ±4 E.I.; M.S. 1962 6

458.1 ±6.3 109.5 ±1.5 Photohalogenation 1963 185 427 ±8 102 ±2 CD3 + CF3 H-*CD3 H+CF: 1964 175

443.5 106.0 Br + CF3 H = HBr + CF3 ; 1966 193 Br + CH4 = HBr + CH3 444.8 106.3 Equilibrium 1966 150 444 ±4 106 ±1 Analysis of data 1966 8

444.8 106.3 Equilibrium 1967 15 423 101 431 103 Thermochemical; 1967 439 ±13 105 ±3 444 ±13 106 ± 3 based on 9

CH3C1 -* CH2 C1 + H 372.0 ±13 88.9±3 1956 124 410 98 Photochlorination 1961 141

CH2 C12 ^CHC12 + H 333.0 ±21 79.6 ±5 E.I.; M.S. 1959 179 397 95 Photochlorination 1961 141

ch3 cn-^ch2 cn + f < 331 < 79 E.I.; M.S. 1961 125

ch3 oh-»ch2 oh+h 385 92 Br+CH3 OH—

1962 139 HBr+ CH2 OH

22
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

c-i ch3 i^ch3 + i 221.7 53.0 A.P.; M.S. 1959 179 230 55 Previous data on 1961 103 HI + CH3 I = CH4 +I2 220.1 52.6 E.I. 1962 6 230 ±4 55 ±1 Equilibrium 1963 65

HI + CH3 I = CH4 +

1

2 227.2 54.3 232.6 55.6 Thermochemical; 1967

226 ±13 54±3 232.2 ±13 55.5 ± 3 based on 9

CNH CN + I 335 80 339 81 Thermochemical; 1967 based on 9

C-N CN —> C + N 808 193 A.P.; M.S. 1961 127 728 ±13 174±3 Shock wave; 1961 120 Kr + C2 N2 812 ±21 194 ±5 816 195 Analysis of various data 1962 6

723.4 ± 9.6 172.9±2.3 Effusion; M.S. 1962 162

732 175 732 175 Thermochemical; 1967 730.1 ±21 174.5 ± 5 732±21 175 ± 5 based on 9

ch3 nh2 -^ch3 +nh2 335 80 A.P.; M.S. 1959 128

331 79 Analysis of data 1966 8 335 80 Thermochemical; 1967

331 ± 13 79 ±3 based on 9

ch3no2 ^ch3 +no2 243 58 Analysis of data 1962 6 238.9 57.1 246.9 59.0 Thermochemical; 1967

247 ±13 59 ±3 based on 9

C-0 co->c+o 1070.23 255.79 1074.83 256.89 Analysis of data 1962 6 1071.77 256.16 1076.38 257.26 Thermochemical; 1967 1071.94 256.2 ±0.1 1076.5 ±0.4 257.3 ±0.1 based on 9 ±0.4

co2 -> co+o 526.14 125.75 532.20 127.20 Thermochemical 1962 6

526.14 125.75 532.16 127.19 Thermochemical; 1967 525.9 ±0.4 125.7 ±0.1 532.2 ±0.4 127.2 ±0.1 based on 9

CH3 OH^CH3 + OH 374.5 89.5 1956 132

381.2 91.1 A.P.; M.S. 1959 179 ~ 377 — 90 Photodissociation 1962 6

381 ±8 91 ±2 Thermochemical 1966 8 370.7 88.6 378.7 90.5 Thermochemical; 1967 370.3 ±13 88.5 ±3 377 ±13 90 ±3 based on 9

HCOOH -» CHO+OH ~ 377 ~ 90 Photodissociation 1962 6

400.4 95.7 Thermochemical; 1967 402 ±13 96 ±3 based on 9

23
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/tmol kcal/mol kj/mol kcal/mol

CH3 COOH^CH3 CO + 0H -377 -90 Photodissociation 1962 6 452.3 108.1 Thermochemical; 1967

452 ±21 108 ± 5 based on 9

ocs^cs+o 619 148 628 150 Thermochemical; 1967 based on 9

c-s cs-^c+s 757 ±151 181 ±36 Spectroscopic; L.B.S. for 1959 20

state 735.5 175.8 740.1 176.9 Thermochemical 1962 6 757 ±21 181 ± 5 761 ±21 182 ± 5

ocs-^co+s 305.0 72.9 310.5 74.2 Thermochemical; 1967

based on 9

cs2 ^cs + s 389 93 397 95 Thermochemical; 1967

based on 9

ch3 s^ch3 +s 289 69 1962 137

ch3 sh^ch3 + sh 305 ±21 73 ±5 Thermochemical; 1962 135 A///(SH) =35.0

293 ±21 70± 5 (T = 400°-500°); 1962 6

E.I.; M.S. 297 71 305 73 Thermochemical; 1967

297 ±13 71 ± 3 305±13 73 ±3 based on 9

ch3 so2 ^ch3 +so2 97.5 ± 7.5 23.3 ±1.8 Thermochemical 1961 142

Ca-Cl CaCl —> Ca + Cl < 266.1 <63.6 Spectroscopic; 1962 6

predissociation.

335 ±42 80 ±10 Calorimetric 1963 186 427 ±25 102 ±6 Flame photometry 1965 23 427±42 1 02 ± 1

CaCl2 —* CaCl + Cl 431 ±42 103 ±10 Flame photometry 1965 23 431 ±42 103 ± 10

Ca-F CaF^Ca + F < 303.8 < 72.6 Spectroscopic; 1962 6

predissociation.

515 ±19 123 ±4.6 Effusion; M.S. 1963 174 565 ± 29 135 ±71

552 ±42 132 ± 10

24
Table ©f Bond Dissociatkfrm Energies -

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/rnol kcal/mol kj/mol kcal/mol

CaF2 —» CaF + F 548 ±42 131 ± 10 Flame photometry; 1965 23

recalculated from

ref. 21. 569 136 Flame photometry 1964 21 548 ±42 131 ± 10

Ca-0 CaO^> Ca + 0 481 ±17 115 ±4 Analysis of data on 1962 6 flames 347 ±42 83 ±10 Theoretical 1964 144 389 ±21 93 ±5 Effusion; M.S. 1964 190

353.1 ±25 84.4 ±6 Effusion; M.S. 1964 189

382.0 ±5.9 91.3 ± 1.4 Flame photometry; 1965 71 CO flame 490 ±21 117 ± 5 Flame photometry; 1965 22 H2 flame

531 ±21 127 ±5 Flame photometry; 1966 191 460 ±84 1 10 ± 20 H2 flame

CaOH-^Ca + OH =£397 ±42 =£95 ±10 Flame photometry; 1957 - 52 C2 H2 + CO flames 418±33 100 ±8 Flame photometry; 1965 22 H2 flame

Ca(OH)2 —» CaOH 490 ± 75 117 ± 18 Ref 191 gives

+OH D\ + D-2 — 217 ± 10 and

22 gives D, = 100 ±8

Ca-S CaS —» Ca + S 289 ±19 69 ±4.6 M.S. 1962 6 332.6 ± 9.6 79.5 ±2.3 M.S.; Effusion of 1963 80

Ca + S2 = CaS + S

308.4 ±18.8 73.7 ±4.5 M.S.; Effusion 1964 189 310±21 74 ±5

Cd-S CdS^Cd + S 377 \v Ono 381 91 Spectroscopic; limit of 1953 1 continuum

=£ 197 e 47 M.S. 1963 80

Cl-Cl Cl2 —> 2C1 238.9 ±0.25 57. 10 ±0.06 242.3 57.9 Spectroscopic 1962 6 239.99 57.36 243.34 58.16 Thermochemical; 1967 239.7 ±0.4 57.3 ±0.1 based on 9

Cl-F C1F —> Cl + F 246.9 ±0.8 59.0 ±0.2 250.2 59.8 Spectroscopic; 1962 6 convergence of bands

251.5 60.1 255.2 61.0 Thermochemical; 1967 248.9 ±2.1 59.5 ±0.5 based on 9 25
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj./mol kcal/mol kj/mol kcal/mol

o3 cif-^o3 ci + f 251 60 A.P.; M.S. 1957 60

255 61 Thermochemical 1962 6

Cl-H HC1 H + Cl 427.60 ±1.46 102.20 ±0.35 431.45 103.12 Thermochemical 1962 6

424.7 101.5 Theoretical 1963 188

428.15 102.33 431.96 103.24 Thermochemical; 1967

428.02±0.42 102.3 ±0.1 based on 9

Cl-0 C10-^Cl + 0 246.9 63.31 Spectroscopic 1958 33

265.01 ±0.13 63.34 ±0.03 269.16 64.33 Spectroscopic; 1962 6

convergence of bands.

264.85 63.30 269.03 64.30 Thermochemical; 1967

267.8 ±4.2 64 ±1 based on 9

C102 ^C10 + 0 267 66 278.2 66.5 Spectroscopic; 1962 6

predissociation 241.0 ±6.3 57.6 ±1.5 245.6 58.7 Thermochemical 1962 6

230 ±8 55 ±2 E.I.; M.S. 1967 27

243.9 58.3 248.5 59.4 Thermochemical; 1967

243 ±13 58 ±3 based on 9

C103 ^ C102 + 0 199.2 47.6 Thermochemical 1962 6

197.1 47.1 Thermochemical; 1967

based on 9 201 ±4 48 ±1

C12 0^C1 + C10 142.7 34.1 146.4 35.0 Thermochemical 1962 6

139.3 33.3 143.1 34.2 Thermochemical; 1967

139.3 ±4 33.3 ±1 based on 9

Co-Co Co2 —> 2Co 163 ±25 39 ±6 Effusion; M.S. 1964 56

163 39 167 40 Thermochemical; 1967

1 64.0 ±1 7 39.2 ±4 based on 9

(CO)4Co-Co(CO)4 48.1 ±19.2 1 1 .5 ± 4.6 A.P.; M.S. 1967 187 -> 2Co(CO)4

Cr-Cr Cr2 —> 2Cr < 167 <40 <172 <41 M.S. 1962 52; 6 < 184 < 44 Effusion; M.S. 1964 56

Cr-O CrO —» Cr + 0 425.5 ±29 101.7 ± 7 Effusion; M.S. 1961 85 418 100 Thermochemical; 1967

423 ±29 101 ± 7 based on 9 26
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Cr02 —» CrO + 0 527 ±63 126 ±15 Effusion; M.S. 1961 85 527 126 Thermochemical; 1967

531 ±63 126 ±15 based on 9

Cr03 —» Cr02 ±0 477 ±84 114±20 Effusion; M.S. 1961 85

Cs-Br CsBr —» Cs + Br 381 91 Effusion; Ioni- 1962 163

zation on hot wire

416.3 ±13 99.5 ±3 M.S. 1962 6

Cs-Cl CsCl—» Cs + Cl 422.2 100.9 425.9 101.8 Effusion; Ioni- 1962 163

zation on hot wire

425.1 ±13 101. 6±3 428.9 102.5 Thermochemical 1962 6 448 ± 13 107 ±3 Flame photometry 1962 6 435 ±21 104 ±5

Cs-F CsF —» Cs + F 481 115 485 116 Effusion; Ioni- 1962 163

zation on hot wire

481 ±25 115 ± 6 485 116 Thermochemical 1962 6 515 ±33 123 ±8 Flame photometry 1962 6

487.4 116.5 Theoretical 1963 188 502 ±42 120± 10

Cs-I Csl —* Cs +

1

315.5 75.4 319.2 76.3 Effusion; Ioni- 1962 163

zation on hot wire

350.2 ± 1

7

83.7 ±4 354.0 84.6 Flame photometry 1962 6 335 ±21 80 ±5

Cs-0 CsOH—» Cs + OH 381 ±13 91 ±3 Flame photometry 1966 192

Cu-Cu Cu2 —» 2Cu 201 ±38 48 ±9 Spectroscopic; L.B.S. for 1962 6

ground state. 190.4 ±9.2 45.5 ±2.2 M.S. 1960; 108;

1 90.4 ±13 45.5 ±3 1962 6

Cu-F CuF Cu + F 293 ±96 70 ±23 297 71 Spectroscopic; L.B.S. for 1953; 3:6

ground state 1962 364 ±38 87 ±9 Effusion; M.S. 1966 151

CuF2 —* CuF + F 366.5 87.6 Effusion; M.S. 1966 151

27
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Cu-H CuH—» Cu + H 276 ±8 66 ±2 280 67 Flame photometry 1956; 136; 1962 6

264 63 Thermochemical; 1967 based on 9

Cu-Sn CuSn —* Cu + Sn 173.2 ±17 41.4 ±4 177.4 42.4 Effusion; M.S. 1962 63; 6

173.4 41.4 Thermochemical; 1967 173.4 ±17 41.4±4 based on 9

F-F F2 -» 2F 153.1 36.6 Thermochemical; M.S. 1956 89

155.2 ±3.6 37. 1 ± 0.85 Spectroscopic; 1957 94 continuous absorption

172.8 ±2.1 41.3 ± 0.5 Molecular beam: 1959 129

magnetic detection

154.8 ±4 37.0 ± 1 159.0 38.0 Dissociation equilibrium 1962 6

161.1 ±2.5 38.5 ±0.6 165.3 39.5 Thermochemical 1962 6

1 70.54 40.76 174.9 ±0.8 41.8± 0.2 Effusion; Knudsen cell 1966 167

153.80 36.76 157.99 37.76 Thermochemical; 1967

1 54.8 ±4 37.0± 1.0 based on 9

F-H HF^H + F 565.3 ±1.3 135.1 ±0.3 566.1 135.3 Spectroscopic; 1959 28

extrapolation of X'S

levels 556.1 132.9 Theoretical 1963 188

561.1 134.1 Shock tube 1965 74

564.0 134.8 568.2 135.8 Thermochemical; 1967

565 ±4 135 ± 1 based on 9

F-0 FO —» F-t- 0 106.3 25.4 A.P.; M.S. 1957 106

184 ±42 44 ±10 189 45.1 Assumed Do(F-O) 1962 6 = l/2D0(F2 O)

151 36 155 37 Thermochemical; 1967 155 ±13 37 ± 3 based on 9

FOO-^F + O, 63 15 Thermal decom- 1965 43

position of F,0,

FoO^FO + F 270.3 64.6 A.P.; M.S. 1957 106 269.9 64.5 274.5 65.6 E.I.: M.S. 1962 66

180 ±42 43 ±10 186.2 44.5 Estimated 1962 6

268 64 272 65 Thermochemical; 1967

268 ±13 64 ±3 based on 9

f2 o, -* fo2 + f 77.8 18.4 A.P.; M.S. 1966 152 28
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Fe-Fe Fe2 Br4 —» 2FeBr2 145.2 ±17 34.7 ± 4 Effusion; M.S. 1959 100

158.2 37.8 Equilibrium 1962 6

studies 172 41 Thermochemical; 1967

1 67 ±17 40 ±4 based on 9

Fe2 CL, -» 2FeCl2 134 ±13 32 ±2 Effusion; M.S. 1958 118

151.9 36.3 Equilibrium 1962 6

studies 142 34 Thermochemical; 1967 146 ±13 35 ± 3 based on 9

Fe-Br FeBr3 —» FeBr2 4- Br 222 53 Thermochemical 1962 6 188 45 Thermochemical; 1967

188 ±21 45 ±5 based on 9

Fe-Cl FeCl.i —> FeCl2 + Cl 209 50 Thermochemical 1962 6

227.2 54.3 Thermochemical; 1967

226±8 54±2 based on 9

Fe-I Fels -* Fel2 + I 144 34.4 Equilibrium studies 1962 6 96 23 Thermochemical; 1967 based on 9

Fe-S FeS —» Fe + S =£ 315.9 =£ 75.5 M.S.; Fe + S2 = FeS + S 1963 80

Ga-Br GaBr—» Ga+ Br 415.5 ±0.4 99.3 ±0.1 419.7 100.3 Spectroscopic 1960 140

429.3 ± 1 7 102.6 ±4 Flame photometry 1962 6 435 104 439 105 Thermochemical; 1967

435 ±17 104 ±4 444 ±1

7

106 ±4 based on 9

Ga-Cl GaCl-^Ga + Cl 474.9 ±4 1 13.5 ± 1 478.2 114.3 Spectroscopic 1960 140

480.7 ±17 114. 9±4 Flame photometry 1962 6 477 114 477 114 Thermochemical; 1967

477 ±13 1 14 ± 3 based on 9

Ga-F GaF —» Ga + F 602.1 ±21 143.9 ±5 605.8 144.8 Spectroscopic 1960 140 577 ±15 138 ±3.5 Effusion; M.S. 1966 170 602 144 607 145 Thermochemical; 1967 602 ±13 144 ±3 based on 9

29
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K

kj/mol kcal/mol

298 K

kj/mol kcal/mol

Method, remarks Date Ref.

Ga-Ga Ga2 —* 2Ga

Ga-H

Ga-I

Ga-0

Ge-C

Ge-Cl

GaH^Ga + H

Gal —* Ga +

GaO —» Ga + O

GaOH—>• Ga + OH

=£ 146

113 113 ±17

272

335

381 ±29

351

351 ±21

343 ±50

293 ±42

347

243

247 ±42

427 ±21

427

431 ±21

Ge-Br GeBr—»Ge + Br 251 ±29

351 251 ±29

GeBr2 —* GeBr + Br

GeC —» Ge + C

GeCl —» Ge + Cl

456 ±21

456

339 ±21

339

\339±21

35

2727±4

65

80

91 ±7

84

84 ±5

58 ±12

70 ±10

8358 59 ± 10

102 ±5

102 103 ±5

50 ±7

60

<> 0±7

109 ±5

109

81 ±5

81 81 ± 5

151

117

117 ±17

276

356

356 ±21

297

351

247

431

255

151

410

460

343

343

343 ±21

36

28

28 ± 4

66

8585 ± 5

7184

59

103

61

50

98

110

82

82

M.S.

Thermochemical;

based on 9

Thermochemical;

based on 9

Spectroscopic

Flame photometry

Thermochemical;

based on 9

Spectroscopic;

L.B.S. for ground state Spectroscopic

Estimate

Thermochemical;

based on 9

Flame photometry

Thermochemical;

based on 9

1957

1967

1967

1960

1962 1967

1953

1962

1962 1967

1958

1967

30;29

1406

1 %

Spectroscopic;

extrapolation

of 2 II state Thermochemical;

based on 9

Thermochemical;

based on 9

M.S. Thermochemical;

based on 9

Spectroscopic;

extrapolation

of 2 A levels Thermochemical;

based on 9

1953

1962

1967

1967

1959

1967

1953

1962

1967

3; 6

123

3; 6

30
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Ge-F GeF^Ge + F 477 ±84 114±20 481 115 Spectroscopic; L.B.S. 1962 6

for x2 n

485 116 490 117 Thermochemical; 1967 484 ±42 1 15 ± 10 based on 9

GeF2 —» GeF + F 548 131 Thermochemical; 1967 based on 9

Ge-Ge Ge2 -* 2Ge 268 ±21 64 ± 5 Effusion; M.S. 1959 123 276 66 280 67 Thermochemical; 1967

272 ±21 65 ±5 280±21 67 ± 5 based on 9

Ge2 H8 —^

*

2GeH.i 142 34 Pyrolysis 1962 6 315.9 75.5 A.P.; M.S. 1966 153

Ge-H GeH-^Ge+H 318 76 322 77 Thermochemical 1962 6

GeFG -> GeH3 + H 365 87.2 A.P.; M.S. 1966 153

Ge-0 GeO —> Ge + 0 657 ±17 157 ±4 L.B.S. for X>2 1962 6 665 ±17 159 ±4 669 160 Thermochemical 1962 6 665 159 674 161 Thermochemical; 1967 669±21 160± 5 674 ±21 161 ±5 based on 9

Ge-S GeS —* Ge + S 544 ± 13 130 ±3 548 131 Spectroscopic; extrapola- 1962 6

tion of E state levels. 556 133 565 135 Thermochemical; 1967 556 ±1 7 133 ±4 561 ±17 134±4 based on 9

Ge-Se GeSe —» Ge + Se 479.1 ±25 1 14.5 ± 6 482.8 115.4 Spectroscopic; extrapola- 1962 6

tion of E state levels. 502 120 506 121 Thermochemical; 1967 502 ±25 120 ± 6 506 ±25 121 ±6 based on 9

Ge-Si GeSi —* Ge + Si 297 ±21 71 ±5 Effusion; M.S. 1959 123 297 71 301 72 Thermochemical; 1967 297 ±17 71 ±4 301 ±17 72 ±4 based on 9

H3GeSiH3 -» GeH3 418.0 99.9 M.S. 1966 153 + SiH 3 31
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Ge-Te GeTe —> Ge + Te 393 ±42 94 ±10 397 95 Spectroscopic; extrapola- 1962 6

tion of E state 398 ± 1 7 95 ±4 Spectroscopic; 1964 72 thermochemical

393 94 397 95 Thermochemical; 1967

393 ±21 94 ±5 397 ±21 95 ±5 based on 9

GeTe> -* GeTe + Te 188 45 Thermochemical; 1967 based on 9

H-H H2 2H 432.027 103.257 436.0 104.2 Spectroscopic 1960 31 ±0.004 ±0.001

432.195 103.297 Theoretical 1966 195 432.00 103.25 435.93 104.19 Thermochemical; 1967

432.00 103.25 based on 9 ±0.04 ±0.01

HD^H + D 435.458 104.077 Spectroscopic 1960 31 435.642 104.121 Theoretical 1966 195

435.43 104.07 439.32 105.00 Thermochemical; 1967

435.43 104.07 based on 9 ±0.04 ±0.01

D2 —» 2D 439.567 105.059 Spectroscopic 1960 31 439.747 105.102 Theoretical 1966 195

439.53 105.05 443.34 105.96 Thermochemical; 1967

439.53 105.05 based on 9 ±0.04 ±0.01

Hf-0 HfO—» Hf+ 0 764.0 182.6 ±6 Effusion; M.S. 1963 92

772 184.6 Thermochemical; 1967

774 ±21 185 ±5 based on 9

Hg-Br HgBr— Hg± Br 71 17 Toluene carrier 1956 154

pyrolysis 68.6 16.4 72.8 17.4 Spectroscopic; extrapola- 1960 32 68.6 ± 4 16.4 ± 1 72.6 ±4 17.4± 1 tion of ground state

Hg-Cl HgCl^Hg + Cl 96 23 Toluene carrier pyrolysis 1956 154 96 ±8 23 ±2 100 24 Spectroscopic; L.B.S. for 1950 4 96 ±8 23 ±2 100 ±8 24 ±2 ground state 32
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Hg-S HgS-»Hg + S 268 ±21 64 ±5 272 65 Spectroscopic; limit of 1953 1 continuum

208.8 s? 49.9 M.S. 1963 80

I-Br IBr —» I + Br 175.381 41.917 177.8 42.5 Spectroscopic 1962 6 ± 0.063 ±0.015

175.39 41.92 177.90 42.52 Thermochemical; 1967 175.3 ±0.4 41.9 ± 0.1 177.8 ±0.4 42.5 ±0.1 based on 9

I-Cl ICWI + C1 208.28 ±0.4 49.78 ±0.1 211.3 50.5 Spectroscopic; con- 1962 6 vergence of bands

207.82 49.67 210.75 50.37 Thermochemical; 1967 207.9 ±0.4 49.1 ± 0.1 21 1.3 ±0.4 50.5 ±0.1 based on 9

I-F IF^I + F 277.0 ±5.0 66.2 ±1.2 280 67 Spectroscopic; graphical 1962 6

extrapolation of Bdl

277.86 66.41 281.50 67.78 Thermochemical; 1967 277.8 ±4 66.4 ±1 280 ±4 67 ± 1 based on 9

I-H HI^H + I 294.60 ±0.42 70.41 ±0.1 298.3 71.3 Thermochemical 1962 6

290.4 69.4 Theoretical 1963 188

294.60 70.41 298.32 71.30 Thermochemical; 1967 294.6 ±0.4 70.4±0.1 298.3 ±0.4 71.3 ±0.1 based on 9

I1

I2 —* 21 148.808 ±0.13 35.566 ±0.03 151.0 36.1 Spectroscopic; band con- 1962 6 vergence

148.963 35.603 151.239 36.147 Thermochemical; 1967 148.95 35.60 based on 9 ±0.04 ±0.01

1-0 10 -» I + 0 176 ±21 42 ±5 Spectroscopic; B.S. 1958 33

extrapolation

239 ±25 57 ±6 Flame photometry 1961 143

184 ±21 44 ± 5 188 45 Spectroscopy; L.B.S. for 1962 6 X-fl and A-n

177.0 42.3 180.7 43.2 Thermochemical; 1967 180 ±21 43 ±5 184±21 44 ± 5 based on 9

33
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kJ//mol kcal/mol kj/mol kcal/n»ol

In-Br InBr—» In + Br 385 ±3 92 ±0.7 Spectroscopic; 1960 140 thermochemical

387.9 ±13 92.7 ± 3 Flame photometry 1961 34

409.6 97.9 412.1 98.5 Thermochemical; 1967 406 ±21 97±5 41 4 ±21 99 ±5 based on 9

In-Cl InCl—» In + Cl 428.4 ±8 102.4 ±2 Spectroscopic; 1960 140 thermochemical

434.7 ±13 103.9 ±3 Flame photometry 1961 34

439 105 Thermochemical; 1967

435 ±8 104 ±2 439±8 105 ± 2 based on 9

In-F InF —* In + F 526.8 ±8 125.9 + 2 Spectroscopic 1960 140 523 ±33 125 ±8 Flame photometry 1961 34

522.2 124.8 525.5 125.6 Thermochemical; 1967

523 ±8 125 ± 2 525 ±8 126±2 based on 9

In-H InH^In + H <238 <57 Spectroscopic; 1950 4

predissociation

243 58 247 59 Thermochemical; 1967

238 ±21 57±5 based on 9

In-I InWIn + I 331 ±4 79 + 1 Spectroscopic; analysis 1960 140

of data 326 ±17 78 + 4 Flame photometry 1961 34

340.6 81.4 342.7 81.9 Thermochemical; 1967 339 ±1

81 ±4 based on 9

In-In In 2 —> 2In 93.7 ±10.5 22.4 ±2.5 Effusion; M.S. 1959 82

103.8 24.8 105.9 25.3 Thermochemical; 1967

100 ±13 24 ±3 100 ±13 24 ±3 based on 9

In-0 InO —* In + 0 96 ±42 23 ±10 Spectroscopic; L.B.S. 1953 1 for ground state 314 75 318 76 Thermochemical; 1962 6

estimate

<318 < 76 M.S.; Effusion; In 2 Os 1963 66

105 25 105 25 Thermochemical; 1967

based on 9 InOH—> IN+ OH 360±29 86 ± 7 Flame photometry 1958 196 360 86 360 86 Thermochemical; 1967

360 ±21 86 ±5 360±21 86 ±5 based on 9

In-S InS -+ In + S 146 35 Thermochemical; 1967

based on 9

In-Sb InSb —

In + Sb 148.1 ±10.5 35.4 ±2.5 Effusion; M.S. 1959 82

161.1 38.5 Thermochemical: 1967

based on 9 34
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

K-Br KBr—> K+Br 379.1 ±4 90.6 ± 1 382.8 91.5 Thermochemical 1953 3 379.5 ±8 90.7 ±2 Flame photometry 1961 34

378.7 ±8 90.5 ±2 382.8±8 91.5 ± 2

K-Cl KC1->K+C1 416.7 ±8 99.6 ±2 Flame photometry 1961 34

423.4 ±1.7 101.2 ±0.4 425.9 101.8 Thermochemical 1962 6 394 94.1 Theoretical 1963 188 423±8 101 ± 2 427 ±8 102 ± 2

K-F KF^K + F 490 ±34 117 ± 8 Flame photometry 1961 34

492.9 ±5.0 117.8 ± 1.2 496.2 118.6 Thermochemical 1962 6 494 118 Theoretical 1963 188 490±21 117± 5 494 ±21 118 + 5

K-I KI —» K +

1

336.4 80.4 Flame photometry 1961 34

322 ±13 77 ±3 326 78 Thermochemical 1962 6 322 77 Theoretical 1963 188 326 ±13 78 ±3 331 ±13 79 ±3

K-0 KOH^K + OH 369.4 88.3 Thermoche mical 1962 6 339 ±8 81 ±2 Flame photometry 1966 192

La-La L&2 ^ 2Ls 241.0 ±21 57.6 ±5 M.S.; photoionization 1963 93

La-0 LaO —

La+ 0 786.2 ±35.6 187.9±8.5 Effusion; M.S. 1956 197

779.5 ±19.2 186.3±4.6 Effusion; M.S. 1961 96 782 ± 21 187 ± 5

La-S LaS —* La + S 573 ±25 137 ±6 Effusion; M.S. 1965 145

Li-Br LiBr—» Li + Br 420.9 ±13 100. 6±3 Flame photometry 1961 34

418 ±13 100 ±3 423 101 Thermochemical 1962 6 418 ±21 100 ± 5 423 ±21 101 ± 5

Li-Cl LiCl—> Li + Cl 462.3 ±13 110.5 + 3 Flame photometry 1961 34

470.7 ±4.6 112.5 ± 1 474.5 113.4 Thermochemical 1962 6 483.3 115.5 Theoretical 1963 188 464 ±13 111+3 469 ±13 1 12 ± 3

Li-F LiF —> Li + F 569 ±34 136 ±8 Flame photometry 1961 34

574.9 ±5.0 137.4+1.2 578.6 138.3 Thermochemical 1962 6 590 141 Theoretical 1963 188 573 ±21 137± 5 577±21 138± 5

35
Table of Bond Dissociatkm Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Li

Lil -* Li +344.3 ±13 82.3 ±3 Flame photometry 1961 34

349.8 ±13 83.6 ± 3 354.0 84.6 Thermochemical 1962 6 341.0 81.5 Theoretical 1963 188

347 ±13 83 ±3 351 ±13 84 ±3

Li-0 LiO —* Li + 0 341.0 81.5 Effusion; M.S. 1959 99

326 ±21 78 ±5 331 79 M.S.; LiO, Li2 0 1962 6

331 ±13 79 ±3 335 ±13 80 ±3

LiOH-^ Li + OH 434.3 103.8 439.3 105.0 M.S. 1960 35

427 102 432 103.2 Flame photometry 1962 6

411.3 98.3 416.3 99.5 Flame photometry 1962 6 423 ±8 101 ±2 Flame photometry 1966 192 423 ±21 101 ±5 427±21 102 ±5

Mg-F MgF —» Mg + F 502 ±84 120 ±20 506 121 Spectroscopic; extrapola- 1962 6

tion of X2X, A-n and

B

2 X

441.4 ±5.0 105.5 ±1.2 M.S.; Effusion; 2MgF 1964 68 = Mg + MgF> 448.9 ±6.7 107.3 ±1.6 M.S.; Effusion; AIF3 1964 68

460 ±42 110±10 + 2Mg= 2MgF + A1F

MgF> — MgF + F 540 ±84 129 ±20 544 130 Thermochemical 1962 6

582.4 ±25 139.2 ±6 M.S.; Effusion; A1F3 1964 68

565 ±42 135 ±10 + 2Mg = 2MgF+ A1F

Mg-0 MgO —» Mg + 0 410 ±8 98 ±2 Flame photometry 1959 177

41 8 ±13 100 ±3 Flame photometry 1962 6

335 80 Transpiration in O2 1963 36

389 93 Transpiration in CL 1963 37

42 ±42 10 ±10 Theoretical 1964 144 360 ±21 86 ±5 M.S.; Effusion 1964 190

377 ±42 90± 10

MgOH —» Mg + OH 234 ±21 56 ±5 Flame photometry 1959 177

Mn-Br MnBr —* Mn + Br 280 ±54 67 ±13 Spectroscopic; L.B.S. of 1950 4 ground state 310.5 ±8 74.2 ± 2 Flame photometry 1961 34

293 ±21 70± 5

36
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Mn-Cl MnCl^Mn + Cl 318 ±63 76 ±15 Spectroscopic; L.B.S. of 1950 4 ground state 356.9 ±8 85.3 ±2 360.7 86.2 Flame photometry 1961 34

335 ±42 80 ± 10

Mn-I Mnl -> Mn'+ I 279.1 ±13 66.7 ±3 283.3 67.7 Flame photometry 1961 34

Mn-Mn Mn2 —* 2 Mn <88 <21 Effusion; M.S. 1964 56

Mn2 (CO)io —

>

142 ±54 34 ±13 (T= 375-419 K); Atfsub. ; 1960 183

2Mn(CO) 5 V.P.

Mn-0 MnO —* Mn + 0 402 ±13 96 ±3 406 97 Flame photometry 1959 176

Mn-S MnS —» Mn + S 298.7 ±17 71.4±4 Effusion; M.S. 1965 114

Mo-0 MoO —> Mo + 0 485 ±63 116 ± 15 M.S. 1960 199

Mo02

* MoO + 0 749 179 Effusion; V.P.; D\+Di 1958 101 = 285

611 ±105 146 ±25 M.S.; £>,+D2 = 262±10 1960 199

669 ±84 160±20

M0O3 —» M0O2 + 0 527 126 Effusion; V.P.; ££ + Do 1958 101 + £>3 = 410.3 623 ±130 149 ±31 M.S.; £>, + £>2 + £>3 1960 199 561 ±84 134±20 = 411.7

N-Br NBr-^N + Br 289 ±59 69 ±14 Spectroscopic; L.B.S. of 1950 4 ground state 280 ±21 67 ±5 Spectroscopic 1961 38

285±21 68 ±5

ONBr-^NO + Br 117 28 Calculated from equilib- 1962 6 rium constants. 116.23 27.78 119.96 28.67 Thermochemical; 1967 116.3±6.3 27.8 ± 1.5 120.1 ±6.3 28. 7 ± 1.5 based on 9

N-Cl NCI—> N + Cl 259 62 Thermochemical 1962 6

« NC12 -*NC1+C1 280 67 Thermochemical 1962 6

nci3 -+nci2 + ci 381 91 Thermochemical 1962 6 37
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

0NCWN0 + C1 155 37 Calculated from equilib- 1962 6 rium constants

156.1 37.3 160.2 38.3 Thermochemical; 1967 155 ±6 37 ± 1.5 159 ±6 38 ± 1.5 based on 9 o2 nci-»no2 +ci 141.4 33.8 Thermochemical 1962 6

138.1 33.0 142.3 34.0 Thermochemical; 1967

138 ±4 33.0 ± 1 1 42.3 ±4 34. 0 ± 1 based on 9

N-F NF —» N + F 251 ±42 60 ±10 255 61 Estimate 1962 6

297 71 Thermochemical 1961 161 297 ±42 71 ± 10 301 ±42 72 ±10

nf2 ->nf+f 295.0 ± 6.7 70.5 ±1.6 Thermochemical; M.S. 1961 107 297 71 Thermochemical 1961 161 332.2 ±42 79.4 ±10 336.8 80.5 Thermochemical 1962 6 314 ±21 75 ±5 318 ±21 76 ±5

nf3 -*nf2 +f 244.3 ± 18.4 58.4 ±4.4 Thermochemical; M.S. 1961 107 238 57 Thermochemical 1961 161 230 55 Thermochemical 1961 126 238 57 A.P.; M.S. 1961 126

238.1 ±21 56.9 ±5 243.5 58.2 Thermochemical 1962 6

241.4 57.7 246.9 59.0 Thermochemical; 1967

238 ±8 57 ± 2 243 ±8 58 ±2 based on 9 ONF^NO + F 231.8 55.4 Calorimetric 1959 182 231.8 ±8 55.4 ±2 236.8 56.6 Thermochemical 1962 6

231.0 55.2 235.6 56.3 Thermochemical; 1967

231 . 0±4 55.2 ±1 235. 6±4 56.3 ±1 based on 9

o,nf->no2 +f 187.0 44.7 Thermochemical; 1962 98

197 ±21 47 ±5 197 ±21 47 ±5

AH° (298) N02F = — 20±5

Thermochemical; from 9 1967

192 ±21 46 ±5 188 ±21 45 ±5

and A//^ (298) N02 F = — 20± 5

N-H NH^N + H 347 ±13 83 ±3 A.P.; M.S. 1958 130

347 ±13 83 ±3 351 84 A.P.; M.S. 1962 6

309.6 ±15 74.0 ±3.7 Spectroscopic; 3 H — 32 — 1966 49

absorption; shock tube

356 85 360 86 Thermochemical; 1967

356 ±8 85 ±2 356 ±8 85 ±2 based on 9 nh2 -^nh + h 385 92 E.I.; M.S. 1959 200

377±17 90 ±4 381 91 Thermochemical 1962 6

377 90 Thermochemical; 1967

372 ±8 89 ±2 377 ± 8.4 90 ±2 based on 9 38
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

nh3 ^nh2 + h 444 ± 13 106 ±3 E.I.; M.S. 1958 105 435 ±8 104 ±2 441.0 105.4 Thermochemical 1962 6 435 104 Thermochemical; 1967

431 ±8 103 ± 2 435 ±8 104 ± 2 based on 9

n2 h4 ^n2 h3 + h 318 ±21 76 ± 5 E.I.; M.S. 1958 105 318 76 E.I.; M.S. 1959 128 318 ±8 76±2

V-N N2 —» 2N 941.69 ±0.46 225.07 ±0.11 945.42 225.96 Analysis of spectroscopic 1962 6 and other data 941.685 225.068 945.408 225.958 Thermochemical; 1967 941 .69 225.07 945.42 ±0.04 225.96 ±0.01 based on 9 ±0.04 ±0.01

N2F4 -*2NF2 115.9 ±29 27.7 ±7 A.P.; M.S. 1960 110

90.0 ±6.7 21.5 ± 1.6 A.P.; M.S. 1961 107

86.6 20.7 A.P.; M.S. 1961 161

83.3 19.9 Equilibrium; NJu 1961 126 = 2NF2 ; Manometer

90.8 21.7 Equilibrium N2F4 1961 126 = 2NF2 ; Spectrophotometric

81.2 ±2.9 19.4 ±0.7 Shock tube dissociation 1965 39

of N2 F4 87.9 21.0 93.3 22.3 Thermochemical: 1967

84±4 20 ± 1 88 ±4 21 ± 1 based on 9

N2 H4 ^2NH2 243 ±38 58 ±9 E.I.; M.S. 1958 105

251 60 A.P.; M.S. 1959 128

259 62 Pyrolysis of N2 H4 1962 6 238.9 57.1 Pyrolysis; Toluene 1963 156

carrier 247 59 Thermochemical; 1967 247 ±13 59 ± 3 based on 9

hn3 -*nh + n2 39.7 9.5 A.P.; M.S. 1958 130

29 7 38 9 Thermochemical; 1967

38 ±4 9 ± 1 based on 9

n2o-^no+n <434.3 ±9.6 < 103.8 ±2.3 A.P.; M.S. 1961 59

475.7 ±4 113.7 ± 1 481.6 115.1 Thermochemical 1962 6 475.09 113.55 480.91 114.94 Thermochemical; 1967 474.9±4 1 13.5 ± 1 480.7 ±4 1 14. 9± 1 based on 9

n2 o3 -»no+no2 36.4 ±4.2 8.7 ±1 41.0 9.8 Equilibrium data 1962 6

35.1 8.42 39.5 9.49 Thermochemical; 1967 35.1 ±0.8 8.4 ±0.2 39.7 ±0.8 9.5 ±0.2 based on 9

39
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

N2 04 -» 2N02 50.84 12.15 54.68 13.07 Equilibrium N2 04 = 2N02 1962 64

53.43 12.77 57.28 ±0.21 13.69 ±0.05 Recalculated equilib- 1962 6 rium data

53.18 12.71 57.20 13.67 Thermochemical; 1967

53.1 ±2.1 12.7 ± 0.5 57.3 ±2.1 13.7 ±0.5 based on 9

Na-Br NaBr-^ Na + Br 366.1 87.5 370.3 88.5 Thermochemical; 1962 6

fluorescence 356.9 85.3 Theoretical 1963 188

366.1 ±13 87.5 ± 3 370.3 ±13 88.5 ± 3

Na-Cl NaCl-^Na + C! 410 ±2 98 ±0.5 410.0 98.0 Thermochemical 1962 6

423.0 101.1 Theoretical 1963 188

410 ±8 98 ±2 410±8 98 ±2

Na-I Nal-^Na + I 301.7 ±8 72.1 ±2 1961 34

295.4 ±0.4 70.6 ±0.1 299.6 71.6 Thermochemical; 1962 6

fluorescence

308.4 73.7 Theoretical 1963 188 297 ±8 71 ±2 301 ±8 72 ±2

Na-0 NaOH-» Na + OH 381 ±13 91 ±3 Thermochemical 1962 6 322 ±17 77 ±4 Flame photometry 1966 192 NaOa-^NaO + O 272 ±13 65 ±3 Flame photometry 1966 194

Nd-F NdF-»Nd + F 545.2 ±12.6 130.3 ±3.0 Effusion; M.S. 1966 171

Nd-0 NdO Nd + 0 692.9 ±28.9 165.6 ±6.9 Effusion; M.S. 1960 96 690 ±25 165 ±6 695 166 M.S. 1962 6 690 ±42 165 ± 10 695 ±42 166± 10

Ni-Br NiBr—» Ni + Br 356 ±13 85 ±3 360 86 Flame photometry 1961 34

Ni-Cl NiCl—» Ni + Cl 368 ±21 88 ±5 372 89 Flame photometry 1961 34

314 75 Thermochemical 1962 6

347 ±42 83 ± 10

Ni-I Nil — Ni + I 289 ±21 69 ±5 293 70 Flame photometry 1961 34

Ni-Ni Ni 2 —» 2Ni 228.0 ±2.1 54.5 ±0.5 Effusion; M.S. 1964 76 40
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

0-H 0H-^0 + H 431.4 ±19.2 103.1 ±4.6 A.P.; M.S.; 1956 Ill Spectroscopic 1961 40

424.09 ±1.3 101.36 ± 0.3 428.19 102.34 Spectroscopic; 1962 6

extrapolation of

A-’FI and B-£.

424.09 101.36 428.19 102.34 Thermochemical; 1967 423.8 ±2.1 101.3 ± 0.5 428.0 ±2.1 102.3 ±0.5 based on 9.

H2 0^0H + H 485.3 ±19.2 116. 0± 4.6 A.P.; M.S. 1956 111 485.8 ±4.2 116.1 ± 1.0 490.8 117.3 Spectroscopic [OH] 1961 41 488.3 116.7 A.P.; M.S. 1958 198

492.5 117.7 Recalculation of data 1959 88 from Ref. 198. 493.7 ±0.1 118.0 ±0.03 498.7 119.2 Thermochemical 1962 6 493.63 117.98 498.73 119.20 Thermochemical; 1967 493.7 ±0.8 1 18.0 ± 0.2 498.7 ± 0.8 1 19.2 ± 0.2 based on 9 ho2 ^h + o2 197 ±13 47 ±3 201.7 48.2 A.P.; M.S. 1956 111 192 46 197 47 Thermochemical; 1967

1 92 ±13 46 ±3 197 ±13 47 ± 3 based on 9

h2 o2 -*ho2 + h 369.0 88.2 374.5 89.5 A.P.; M.S. 1956 111 365.3 ±8 87.3 ±2 370.7 88.6 Thermochemical 1962 6 372 89 377 90 Thermochemical; 1967 370.3 ±8.4 88.5 ±2.0 374.5 ± 8.4 89.5 ±2. based on 9

0-0 02 —* 20 493.59 ±0.21 117.97 ±0.05 498.40 119.12 Spectroscopic; extrapo- 1962 6

lation of B

:! X /jl. 493.570 117.966 498.340 119.106 Thermochemical; 1967 493.59 ±0.4 117.97 ±0.1 based on 9

ho2 -±oh+o 266.1 ±8 63.6 ±2 271.5 64.9 Thermochemical 1962 6 259 62 268 64 Thermochemical; 1967 264.4±4 63.2 ± 1 based on 9

H2 02 —» 20H 203.8 48.7 210.5 50.3 Photochemical 6

200.0 ±13 47.8±3 E.I.; M.S. 1958 198

202.5 48.4 Recalculation of 1959 88

Ref. 198 data

198.74 47.50 Kinetic 1958 42

204.2 48.8 Kinetic 1959 87

209.2 ±13.4 50.0± 3.2 A.P.; M.S. 1962 119

207.36 ±1.46 49.56 ±0.35 214.14 51.18 Thermochemical 1962 6

207.44 49.58 214.22 51.20 Thermochemical; 1967 207.1 ±2.1 49.5 ±0.5 21 3.8 ±2.1 51.1 ± 0.5 based on 9

fo2 -+fo + o 463.2 110.7 A.P.; M.S. 1966 152

41
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

F2 02 —» 2F0 259.8 62.1 Thermochemical; 1959 131 assumptions of O-F

bond energies 260.7 ±84 62.3 ±20 Thermochemical 1962 6

434.3 103.8 A.P.; M.S. on F2 02 1965 149 326 78 Thermochemical; 1967

based on 9

Os-O 0s04 —* 0s02 + 0 452 108 A.P.; M.S. 1965 147

302.9 72.4 Thermochemical; 1967

based on 9

301 ±21 72 ±5

P-0 PO^P + O 592.0 ±2.5 141.5±0.6 595.4 142.3 Spectroscopic; con- 1962 6 vergence of B

2 £ levels 520.9 124.5 Theoretical 1965 146 592.0±4 141 . 5±1 595.4 ±4 142.3 ±1

P-P P2 ^2P 485.60 ±0.38 116.06 ±0.09 489.07 116.89 Spectroscopic; pre- 1962 6

dissociation of B'2;

graphical extrapolation

of Xl 2

472.8 113 A.P.; M.S. 1963 172

467.8 111.8 Effusion; M.S. (3rd law) 1966 165

511.7 122.3 Effusion; M.S. 1966 165

(2nd law)

481 115 485 116 Thermochemical; 1967 481 ±8 1 15 ± 2 485 ±8 1 16 ± 2 based on 9

P2 C14 ^2PC12 243 58 A.P.; M.S. 1963 172

Pb-0 PbO^Pb + O 391. 6 ±3.3 93.6 ±0.8 396.6 94.8 Thermochemical 1962 6

369.9 ±5.9 88.4 ±1.4 A.P.; M.S. 1965 180

377 ±13 90 ±3 381 ±13 91 ± 3

Pb-S PbS-^Pb + S 305 ±21 73 ±5 310 74 Thermochemical 1962 6

331.0 ± 12 79.1 ±2.8 Effusion; M.S. 1962 84 318±21 76 ±5 322 ±21 77 ± 5

Pb-Se PbSe —» Pb + Se 257.3 ±10.5 61.5 ± 2.5 Effusion; M.S. 1961 159

257.3 ±10.5 61.5±2.5 261.1 62.4 M.S. 1962 6 257.3 ±10.5 61.5 ± 2.5 261.1 ±10.5 62 . 4 ± 2.5

42
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Pb-Te PbTe —» Pb + Te 215.1 ±8.4 51.4±2.0 Effusion; M.S. 1961 159

215.1 ±8 51.4 ± 2 218.8 52.3 M.S. 1962 6 215.1 ±8 51.4 ±2 21 8.8 ±8 52.3 ±2

Rb-Br RbBr—» Rb + Br 383.7 ±8 91.7 ±2 Flame photometry 1961 34

385 ±25 92 ±6 Thermochemical 1962 6 385±25 92 ±6

Rb-Cl RbCl—» Rb + Cl 424.7 ±8 101.5 ±2 Flame photometry 1961 34

459.4 ± 13 109.8 ±3 463.2 110.7 Thermochemical 1962 6 444 ±21 106 ± 5 448 ±21 107 ± 5

Rb-F RbF-^Rb + F 502 ±33 120±8 Flame photometry 1961 34

477 ± 13 1 14 ± 3 480.3 114.8 Thermochemical 1962 6 490 ±21 117±5 494 ±21 1 18 ± 5

Rb-I Rbl —» Rb + I 339.7 ±8 81.2 ±2 Flame photometry 1961 34

323.0 ±13 77.2 ±3 326.8 78.1 Thermochemical 1962 6 331 ±13 79 ±3 335±13 80 ±3

Rb-0 RbOH^Rb + OH 347 ±8 83 ±2 Flame photometry 1966 192

Ru-0 Ru04 —» RuOs + 0 435 104 A.P.; M.S. 1965 147

S-F so2 f^so2 + f 67.53 16.14 A.P.; M.S. 1958 117

so2 f2 -*so2f+f 656.1 156.8 A.P.; M.S. 1958 117

sf6 -*sf5 +f =£ 326 ^78 A.P.; M.S. 1961 160

S-H HS—» H + S 340.6 ±12.1 81.4±2.9 344.3 82.3 Spectroscopic; ex- 1962 6

trapolation of A2S

351 84 356 85 Thermochemical; 1967 349.4 ±6.3 83.5 ±1.5 353.1 ±6.3 84.4 ±1.5 based on 9

H2 S^HS+H 379.5 90.7 384.9 92.0 ±3 Thermochemical 1962 6 377 90 381 91 Thermochemical; 1967 377 ±4 90 ±1 381 ±4 91 ± 1 based on 9

43
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

S-0 SO -+ S + 0 497.1 118.8 A.P.; M.S. 1958 117

531.8 127.1 Spectroscopic; B.S. 1962 45

extrapolation 517.02 ±0.13 123.57 ±0.03 521.70 124.69 Spectroscopic; pre- 1962 6

dissociation 516.7 123.5 Spectroscopic 1964 77

517.1 123.6 Spectroscopic; ex- 1965 75 amination of data

517.1 123.6 521.7 124.7 Thermochemical; 1967 517.1 ±8 123.6 + 2 based on 9

so2 ^so+o 385 ±29 92 ±7 A.P.; M.S. 1957 44

548 131 Thermochemical; 1959 113 secondary scource

541.58 ±1.3 129.44 + 0.3 546.51 130.62 Thermochemical 1962 6

515.9 ±33.5 123.3 ±8 Spectroscopic; 1964 77 continuum limit 547.3 130.8 552.3 132.0 Thermochemical; 1967 547.3 ±8 130.8+2.0 based on 9

S0:! -+S02 ±0 341.83 ±0.63 81.70 + 0.15 347.3 83.0 Thermochemical 1962 6 342.50 81.86 348.07 83.19 Thermochemical; 1967

342.7 ±4 81.9± 1 348.1 ±4 83.2 ± 1 based on 9

s-s S 2 -*2S 414.6 99.1 Secondary source 1959 112 424.3 101.4 Theoretical 1961 158

412.1 ±2.5 98.5 + 0.6 417.6 99.8 Thermochemical 1962 6

424.7 101.5 Dissociation 1963 81 equilibrium; M.S.

407.5 ±18.8 97.4±4.5 Effusion; M.S.; CaS 1964 189

391.2 ±29 93.5 + 7 Effusion; M.S.; SrS 1964 189

395.8 ±23.0 94.6 ±5.5 Effusion; M.S.; BaS 1964 189

425.1 101.6 429.3 102.6 Thermochemical; 1967 424.7 ±6.3 101.5 ±1.5 428.9 ±6.3 102. 5± 1.5 based on 9

H,S, -»• 2HS 261.9 62.6 Theoretical 1961 158

277.0 ±25 66.2 ±6 Thermochemical 1962 6

247 ±13 59 ±3 A.P.; M.S. 1962 97

274.9 65.7 Thermochemical; 1967 272 ±21 65 ± 5 based on 9

Sb-Sb Sb2 —* 2Sb 295.4 ±6.3 70.6 ±1.5 299.6 71.6 Effusion; M.S. 1959 82

Sb-Te SbTe^Sb + Te 251.0 60.0 Effusion; M.S. 1960 61 44
Table of Bond Dissociation Energies — Confirmed

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Sc-Sc Sc 2 2Sc 108.4 ±21 25.9 ±5 Effusion; M.S. 1963 93

Sc-F ScF —» Sc + F 506 ± 71 121 ±17 Spectroscopic; L.B.S. 1962 46

Si-H SiH-*Si + H 310 ±25 74 ±6 314.2 75.1 Spectroscopic; 1957 47

extrapolation of 2 A

SiH 4 —» SiH:( + H 335 80 Thermochemical 1962 6

398.3 95.2 M.S. 1966 153

Sn-0 SnO —» Sn + 0 561 ±8 134 ±2 565 135 Equilibrium 1962 6 Sn02 + Sn = 2SnO

529.3 ± 8.4 126.5 ±2.0 A.P.; M.S. 1965 181 544 ±21 130 ± 5 548 ±21 131 ± 5

Sn-S SnS —* Sn + S 469 ±13 112 ±3 473 113 Thermochemical 1962 6 460 ± 13 1 10 ± 3 Effusion; M.S. 1962 84 464 ±21 111 ±5 469±21 1 12 ± 5

Sr-Cl SrCl—> Sr + Cl 289 ±59 69 ±14 293 70 Spectroscopic; L.B.S. of 1962 6 ground state 410 ±25 98 ±6 Flame photometry 1965 23 335 ±84 80±20 339±84 81 ±20

SrCl 2 —* SrCl + Cl 611 ±59 146 ±14 Thermochemical 1962 6 418 ±25 100 ±6 Flame photometry 1965 23

Sr-F SrF —» Sr + F 335 ±67 80 ±16 339 81 Spectroscopic; L.B.S. of 1962 6 ground state 525.5 ± 13 125.6 ±3 Effusion; M.S. 1964 68

2SrF= Sr+ SrF2 552 ±29 132 ±7 Flame photometry 1965 23 540 ±42 129± 10

SrF2 ~* SrF + F 774 ±67 185 ±16 Thermochemical 1962 6 578.2 ±21 138.2 ±5 Effusion; M.S. 1964 68

2SrF = Sr+SrF,

556 ±42 133 ±10 Flame photometry 1965; 23 565 ±42 135 ± 10 1966 21 45
Table of Bond Dissociation Energies — Continued

Dissociation energy, D°

Bond Reaction 0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Sr-0 SrO—» Sr + 0 469 ±8 112 ± 2 472 ±4 112.9 Flame photometry analy- 1962 6

sis of various data 427 ±42 102 ±10 Theoretical 1964 144 385 ±25 92 ±6 Effusion; M.S. 1964 189

396.6 94.8 Flame photometry; CO 1965 71 flame 515 ±21 123 ±5 Flame photometry; H2 1966 191 460 ±84 110±20 flame

SrOH—» Sr + OH 377 ±42 90 ± 10 Flame photometry; C 2 H2 1957 52 + CO flame

410 ±63 98 ±15 1965 22

Sr(OH)2 -» SrOH 490 ±113 117 ±23 Ref. 191 gives D\ + D2 + OH = 215 ±12 and 22

gives D2 = 98 ± 15

kcal mol-1

Sr-S SrS —» Sr + S 222 ±21 53 ±5 226 54 Spectroscopic; long 1962 6

\ of continuum

335 80 Effusion; M.S. 1963 80

310.0 ±18.8 74.1 ±4.5 Effusion; M.S. 1964 189

31 4 ±42 75 ±10

Ta-0 TaO -* Ta + 0 810.4 ±50 193.7 ±12 Effusion; M.S. 1957 115

Te-Se TeSe Te + Se 241.0 57.6 Effusion; M.S. 1960 61

Te-Te Te2 —* 2Te 218 ±8 52 ±2 Effusion; M.S. 1961 159

Th-0 ThO^Th + O 820 196 824 197 M.S. 1962 6

<820 < 196 Effusion; M.S. 1963 173

Th02 —» ThO + 0 < 770 < 184 Effusion; M.S.; Ref. 173 1963 173

gives D\ + D2 < 375.9

kcal mol -1

Ti-0 TiO—> Ti + O 653 ±25 156 ±6 657 157 M.S. 1962 6

541.4 129.4 Theoretical 1964 78

Ti-Ti Ti 2 -> 2Ti <243 <58 Effusion; M.S. 1964 56

46
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D

°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

Tl-Br TlBr-^Tl + Br 328.0 78.4 331.8 79.3 Thermochemical; 1960 140

spectroscopic data

324.7 77.6 Flame photometry 1961 34

326 ±21 78 ±5 331 ±21 79 ±5

Tl-Cl T1C1 —» T1 + Cl 377 90 Thermochemical; 1960 140

spectroscopic data 364 ±8 87 ±2 Flame photometry 1961 140

Tl-F T1F —» T1 + F 460 110 Thermochemical; 1960 140

spectroscopic

460 ±42 110 ± 10 Flame photometry 1961 34

452 ± 10.5 108 ±2.5 Calorimetry 1965 148 423 ± 14.6 101 ±3.5 Effusion; M.S.; Tl+MgF 1966 170

439±21 105 ± 5 = T1F + Mg

Tl-I Til —> T1 +

1

272 ± 13 65 ±3 276 66 Thermochemical 1960 140 285 ±13 68 ±3 Flame photometry 1961 34

280 ±21 67 ± 5 285±21 68 ±5

U-0 uo-^u+o 749 ±29 179 ±7 M.S. 1960 199

U02 ^U0+0 674 ±59 161 ±14 M.S. 1960 199

uo3 ^uo2 + o 640 ±88 153 ±21 M.S. 1960 199

U-S US^U + S 561 ± 9.6 134±2.3 Effusion; M.S. 1966 168

v-o vo^v+o 617.6 ± 19.2 147.6±4.6 Effusion; M.S. 1957 116

vo2 ^vo+o 61 7.6 ± 19.2 147.6 ±4.6 Effusion; M.S. 1957 116

W-0 wo^w+o 678 ±42 162 ±10 M.S.; Effusion 1959 83 644 ±42 154 ±10 M.S.; partial 1960 199 661 ±42 158 ± 10 pressure

47
Table of Bond Dissociation Energies — Continued

Bond Reaction

Dissociation energy, D°

0 K 298 K Method, remarks Date Ref.

kj/mol kcal/mol kj/mol kcal/mol

wo2 ^wo+o 661 ±42 158 ± 10 M.S.; Effusion 1959 83 594 ± 71 142 + 17 M.S.; partial 1960 199

628 ±84 150 + 20 pressure

wo3 -* W02 + 0 573 ±42 137 + 10 M.S.; Effusion 1959 83 615 ±100 147 ±24 M.S.; partial 1960 199

594 ±42 142 ±10 pressure

Y-La Yla-+Y + La 197 47 Effusion; M.S. 1963 93

Y-Y Y2 -+2Y 156.1 ±21 37.3 ± 5 Effusion; M.S. 1963 93

Zn-S ZnS—* Zn + S 406 ±29 97 ±7 410 98 Spectroscopic; 1962 6

continuum limit 203.8 48.7 Effusion; M.S.; 1963 80

ZnS —* Zn + 1/2 S 2 201 ±13 48 ±3 Effusion; M.S. 1965 184 201 ±13 48 ±3

Zn-Se ZnSe —» Zn + Se 132.6 ±12.6 31.7 ±3.0 Effusion; M.S. 1965 184

Zr-0 ZrO —* Zr + 0 753 ±21 180±5 Effusion; M.S. 1957 121

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