bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave Absorption in Compressed Gases; Saturated Hydrocarbons
Authors: Maryott A. A. , Birnbaum G.
Published: January 2005

Sensitive resonant cavity techniques were used to search for dielectric loss in the lower members of the saturated hydrocarbon series, C1 through C5, at several frequencies in the range 2 to 24 kMc/sec. No detectable loss was found in methane (tanδ<8×10—7) or ethane (tanδ<4×10—7) up to the highest pressures examined, 69 and 36 atmos, respectively. Significant loss attributable to the presence of small permanent dipole moments was found in propane, isobutane, and isopentane. The results for isobutane, which show nonresonant or Debye type absorption characteristic of a symmetric top inversion spectrum having ``zero'' frequency, lead to an accurate evaluation of the dipole moment, namely 0.132 D. The effective collision diameters for impacts governing the Debye relaxation in both isobutane and isopentane are larger than the kinetic collision diameters.
Proton Hyperfine Interactions in Semiquinone Ions
Authors: Bersohn R.
Published: January 2005

The proton hyperfine structure in a series of methylsubstituted semiquinone ions has been shown to arise in a general sense from configuration interaction. A crude calculation of the proton hfs to be expected in a hypothetical solution of C2H4+ ions indicates that the σ—π interaction is responsible for the hfs of protons attached directly to an aromatic ring. The molecular orbital theory of hyperconjugation accounts for the detailed hfs associated with the methyl protons.
Iodine Complexes in Inert Solvents. I. I2–I2 in Carbon Tetrachloride and in n-Heptane
Authors: de Maine P. A. D.
Published: January 2005

The shape of the ultraviolet absorption curve for the I2–I2 complex in CCl4 and in n-heptane, has been obtained by analysis of the ultraviolet absorption of iodine dissolved in these pure solvents. In this analysis it has been necessary to assume that the assumed equilibrium constant, for the reaction I2+I2⇌I2—I2, does not change with the wavelength. In carbon tetrachloride and in n-heptane the I2–I2 complex absorption maximum occurs near 2935 A, which is in good agreement with the value predicted by the McConnell, Platt, and Ham relation. The heat of formation of this complex in CCl4, has been estimated as 1.96 kcal/mole (within 0.15 kcal) by assuming that its molar extinction coefficient curve does not change with the temperature.

The absorption spectrum of iodine dissolved in CCl4 has been extended to 2250 A, and it has been shown that iodine-carbon tetrachloride solutions obey Beer's law below 2500 A, a region in which there is strong absorption by CCl4 and no absorption by I2–I2.
Nature of the Hydrogen Bond. III. The Measurement of the Infrared Absorption Intensities of Free and Hydrogen-Bonded OH Bands. Theory of the Increase of the Intensity Due to the Hydrogen Bond
Authors: Tsubomura Hiroshi
Published: January 2005

The integrated intensities of the infrared OH bands of various compounds have been measured for the free and the hydrogen-bonded states. It is found that the integrated intensity of either the free or the hydrogen-bonded OH band increases as the frequency decreases. It is concluded that the main factor increasing the integrated intensity of the intermolecularly hydrogen-bonded OH bands is the charge transfer through the hydrogen bond. The sign of the change of the dipole moment of the free phenol with the OH distance is discussed. An explanation is given for the weakness of the OH bands of the chelate compounds.
Rate of Recombination of Radicals. I. A General Sector Theory; A Correction to the Methyl Radical Recombination Rate
Authors: Shepp Allan
Published: January 2005

We have derived a rotating sector theory applicable to simple photochemical decompositions involving both first-order and second-order removal of radicals. This theory gives the behavior of radicals under intermittent illumination as a function of two parameters: α, the ratio of first- to second-order removal rates, and β, a function of flash time. We use this theory to recalculate the experimental data on the methyl radical recombination rate. We find the constant k2 to be 2.2×1013 cc moles—1 sec—1 in the temperature range 125°C to 175°C.
Rate of Recombination of Radicals. II. The Rate of Recombination of Trifluoromethyl Radicals
Authors: Ayscough P. B.
Published: January 2005

The rotating sector technique has been used to determine the rate of recombination of trifluoromethyl radicals produced by the vapor phase photolysis of hexafluoroacetone. Using the method of calculation described in Part I of this paper the rate constant was found to be 2.3×1013 cc mole—1 sec—1 at 127°C.
Study of Two-Center Integrals Useful in Calculations on Molecular Structure. IV. The Auxiliary Functions Cαβγδε(ρa,ρb) for α≥0
Authors: Roothaan C. C. J.
Published: January 2005

A new method is developed for the numerical computation of the auxiliary functions Cαβγδε(ρa,ρb) which are used in (III) in this series, for the case α≥0. The present method is suitable for all values of the parameter τ = (ρa—ρb)/(ρa+ρb), avoiding the excessive loss of significant figures which occurs in the methods developed in (III) for the physically important case of small τ.
Adsorption Studies on Clay Minerals. VI. Alkali Ions on Attapulgite
Authors: Merriam C. Neale , Thomas Henry C.
Published: January 2005

The exchange equilibria of the alkali ions Cs, K, Na, Li on attapulgite have been studied at 30° and 75°. Thermodynamic data for the systems have been calculated. Cesium is the most strongly adsorbed ion and the others follow in the order given. The specificity of the clay becomes lower at the higher temperature.
Infrared Spectrum of Benzene-d6
Authors: Miller Foil A.
Published: January 2005

Improved infrared data have been obtained for benzene-d6 from 300—3700 cm—1 for both vapor and liquid phases. The frequencies can be interpreted very completely and satisfactorily. Good evidence was found for assigning v14 and v15 to 1287 and 838 cm—1 in benzene-d6. This provides valuable confirmation for Mair and Hornig's choice of 1310 and 1152 in benzene itself. All the fundamental frequencies for both benzene and benzene-d6 now seem to be well established, aside from small uncertainties in a few cases where the values have been inferred from combination tones or from the product rule.

The infrared spectrum of benzene vapor for the range 300—700 cm—1 is also given.
Higher Order Rotation-Vibration Energies of Polyatomic Molecules. I
Authors: Goldsmith Mark , Amat Gilbert , Nielsen Harald H.
Published: January 2005

As a prerequisite for the evaluation of third- and fourth-order perturbation energies of a rotating-vibrating polyatomic molecule, we derive here an appropriate Schroedinger equation and give a preliminary discussion of a useful contact transformation of the Hamiltonian.
Infrared Absorption Anisotropy of Crystalline Iodoform
Authors: Hexter R. M. , Cheung H.
Published: January 2005

The polarized infrared spectrum of crystalline iodoform has been obtained using single crystals of thicknesses from 50 to 200 microns. Spectra were recorded with the crystals oriented with respect to the electric vector by an x-ray diffraction type goniometer, and the anisotropy of the spectrum was studied carefully as a function of angle of orientation.

A complete assignment of all fundamentals was possible, including at least two of the lattice frequencies of the crystal. The anisotropic behavior of v1, the C–H stretching fundamental, is such that it is possible to state that Pimentel's ``oriented gas model'' holds within well-defined limits. It is demonstrated that a much better procedure of locating transition moment directions in crystals than the use of ``dichroic ratios'' is the complete goniometric study of the absorption anisotropy. Finally the ``threefold degenerate'' first overtone of v4, the C–H bending mode, was split, and the intensity ratio of its members is reported.
Elastic and Inelastic Scattering of Low-Velocity H— Ions in Hydrogen
Authors: Muschlitz E. E. , Bailey T. L. , Simons J. H.
Published: January 2005

An improved apparatus for the production of beams of negative ions and the measurement of the elastic and inelastic scattering of negative ions in gases at low pressures in briefly described. The measured cross-sections are given for the scattering of 4—400 ev H— ions in hydrogen. In the range 4—40 ev (1.1—1.8 A) the interaction potential derived from the elastic scattering is V (ev) = —4.64×10—32/r4 (r in cm) which is close to the theoretical polarization interaction. The inelastic scattering is presumed to be due to electron detachment. The inelastic cross section increases from 1 cm—1 at 7 ev to 8.7 cm—1 at 395 ev. Above 75 ev the measured elastic cross section increases with increasing ion energy. This is attributed to the appearance of inelastic collisions which result in electronic excitation of the hydrogen molecules.
Infrared Absorption Spectra of Complex Cobalt Compounds
Authors: Hill Douglas G. , Rosenberg Alexander F.
Published: January 2005

The infrared absorption spectra of finely powdered complex cobalt salts were obtained in the 2 to 15 micron region. Complexed ammonia shows four absorption bands, at approximately 3000, 1600, 1350, and 850 wave numbers. A possible assignment of three of these to N–H vibrations and the lowest to a rocking vibration, as proposed by Mizushima, is discussed. In the trisethylenediamine and hexanitrito complexes a frequency similar to the rocking vibration persists, but other frequencies characteristic of the particular ligands appear instead of N–H bands. A shift in the absorption maxima as the anions are changed shows that the fields of the anions are of importance. Fine structure observed in some of the strong absorption bands might be combinations with lattice vibrations.

A comparison of the absorption spectra of certain hexammines obtained from deposited pure powders and from pressed KBr plates shows differences in details, which may be interpreted as indicating dissociation of the cobalt salt in the pressed KBr plate and an essentially liquid structure for the latter.

The series of complex cobalt compounds whose infrared spectra were reported recently [D. G. Hill and A. F. Rosenberg, J. Chem. Phys. 22, 148 (1954)] has been extended to include a number of hexammines with various anions and several similar series of pentammines. A comparison has been made with a series of hexanitrito cobalt compounds and trisethylenediamine salts. The spectra of some of the compounds mentioned earlier have been remeasured and the range has been extended to the whole spectrum obtainable with a rocksalt prism. This has demonstrated greater complexity in the spectra than we had first imagined, but has led to a better understanding of them. Special care has been taken to insure the purity of all salts used.
Crystal Structure of Gadolinium Orthoferrite, GdFeO3
Authors: Geller S.
Published: January 2005

The crystal structure of gadolinium orthoferrite, GdFeO3, has been determined from single-crystal x-ray data. There are four GdFeO3 distorted perovskite units in the orthorhombic cell with lattice constants a=5.346, b=5.616, c=7.668, all ±0.004 A. The structure is solved on the basis that the most probable space group is D2h(16)— Pbnm. However, although the atomic coordinates lead to very good agreement between calculated and observed reflection amplitudes, there are at least very slight deviations from the centrosymmetric space group because the iron sublattices are imperfectly antiferromagnetic.
Role of Nitric Oxide in the Thermal Decomposition of Nitrous Oxide
Authors: Kaufman Frederick , Gerri Norman J. , Bowman Roger E.
Published: January 2005

The rates of decomposition of N2O and of formation of NO were measured simultaneously in a static system. NO yields at the beginning of reaction are as high as 50 to 60%, but NO quickly inhibits its own further formation. From initial NO yields, information about the reaction of oxygen atoms with N2O and about wall recombination was obtained. Limiting NO pressures for complete N2O decomposition were interpreted in terms of the reaction NO+O+M→NO2+M, and its rate constant was calculated. The effect of increased surface area and of added gases was studied. The halogens were found to be efficient inhibitors of NO formation.

The chemiluminescence of reacting N2O was observed and its dependence on temperature, pressure, and added gases studied. All evidence points to the reactionO+NO→NO2+hνas its origin. Inhibition of NO formation and of chemiluminescence is shown to be closely related.
Electronic and Vibrational States of Anthracene
Authors: Sidman Jerome W.
Published: January 2005

The polarized absorption and fluorescence spectra of anthracene have been measured in dilute solid solution in single crystals of naphthalene and phenanthrene at 20°K. The lowest singlet-singlet transition is proven to be polarized along the short molecular axis, and hence 1B2u—1Ag(1La—1A), in agreement with theoretical predictions. Vibrational frequencies are compared in the ground state and in the first excited state. The polarization of the fluorescence of anthracene in phenanthrene has also been studied as a function of temperature. The fluorescence is partially polarized at 300°K, but is depolarized at 20°K.
Theory of Radiation Chemistry. III. Radical Reaction Mechanism in the Tracks of Ionizing Radiations
Authors: Ganguly A. K. , Magee J. L.
Published: January 2005

This paper develops a model for the dissipation of the tracks of high-energy particles. It is assumed that all chemical effects are due to one kind of radical and that there are no effects of overlapping of neighboring tracks, i.e., that there is a sufficiently high concentration of scavenger to prevent such overlapping. The model of Samuel and Magee is used and extended to take into account the interaction of randomly distributed spurs along the track. Calculated values of the extent of scavenger reactions and radical reactions are presented in graphical form. General trends of experimental results to be expected according to the model are indicated. Quantitative correlation with experiments was not attempted because of the uncertainty in the values of various parameters used and because of the serious limitations of the one-radical model of tracks.
Some Bromine, Iodine, and Indium Nuclear Quadrupole Interaction Frequencies
Authors: Ludwig G. W.
Published: January 2005

Quadrupole interaction frequencies due to Br79 and I127 are reported in a number of crystalline solids. Br79 interaction frequencies in bromobenzene derivatives and I127 frequencies in iodobenzene derivatives are correlated with Hammett's σ. The splitting between interaction frequencies found in s-tribromophenol and related di- and tribromobenzene derivatives is explained tentatively on the basis of hindered rotation. Coupling constants and asymmetry parameters for I127 in iodobenzene derivatives are reported and discussed in terms of the single bond, double bond, and ionic character of the carbon-iodine bond. Owing to the large asymmetry (∼45%) of the I127 quadrupole coupling in HIO3, |Δm| = 2 transition could be observed as well as the two |Δm| = 1 transitions. Eight interaction frequencies were found in InI3, two of which (at 26.93 Mc/sec and 36.33 Mc/sec) are attributed to (±7/2 ↔±5/2) and (±9/2 ↔±7/2) transitions of In115. From these two frequencies a coupling constant and asymmetry parameter of 219.8±0.3 Mc/sec and 32.0±4.0%, respectively, are evaluated for In115 in this compound.
Pyrolysis of Dimethyl Ether
Authors: Benson Sidney W.
Published: January 2005

An analysis of the published data on the pyrolysis of dimethyl ether shows that the reaction can be interpreted as a chain decomposition initiated by CH3OCH3→CH3+OCH3, terminated by CH3 radical recombination and accelerated by the chain transfer reaction CH3+H2→CH4+H. A simplified Rice-Herzfeld mechanism then gives for the over-all rate of reaction the expression −d(Me2O)dt=k0(Me2O)12[1+β(CH2O)(Me2O)+α(H2)(Me2O)]where k0=k2(k1/k10)½; k2 representing H abstraction by CH3 from Me2O and k10, CH3 recombination.

The data yield a value of k0=4.31×10—3 (liter/mole)½ sec—1 at 777°K. Using published data on k2 and k10, an estimated activation energy E1=81.1 kcal and an estimated value of ΔS10=38 cal/mole-°K one finds A1=6.1×1016 sec—1 and for the reverse reaction to 1, A—1=7.0×109 liter/mole sec. The data do not permit evaluation of β while α is in the range 0.3 to 0.4 for both H2 and D2. Independent calculations of α yield the values 0.8 for H2 and 0.6 for D2, both calculations having a probable error of a factor of 2. For the over-all activation energy of the 32; order chain, E0=50.0 kcal.

It is proposed that the observed exchange of Me2O with D2 is a heterogeneous reaction.
Thermal Diffusion near the Critical Solution Point
Authors: Thomaes G.
Published: January 2005

Thermal diffusion measurements have been carried out near the critical solution point by means of a new apparatus which will be described in another paper. The Soret coefficient D′/D for nitrobenzene+n-hexane shows a large increase in the vicinity of this point. This is a strong argument in favor of the existence of a thermodynamical factor in the isothermal diffusion coefficient as predicted by the thermodynamics of irreversible processes.
Relaxation of Vibrational Nonequilibrium Distributions. II. The Effect of the Collisional Transition Probabilities on the Relaxation Behavior
Authors: Rubin Robert J. , Shuler Kurt E.
Published: January 2005

In order to test the influence of the collisional transition probabilities on the relaxation behavior of initial vibrational nonequilibrium distributions, we have used collisional transition probabilities which increase exponentially with an increase in the vibrational quantum number. The results obtained for this set of transition probabilities are compared with the results obtained for the Landau-Teller transition probabilities which increase linearly with an increase in the vibrational quantum number. Numerical calculations for the relaxation of various initial δ function and Boltzmann distributions show that the detailed relaxation behavior depends quite strongly on the form of the collisional transition probabilities.
Heat Capacity of Dysprosium from 15 to 300°K
Authors: Griffel Maurice , Skochdopole R. E. , Spedding F. H.
Published: January 2005

The heat capacity of dysprosium has been measured over the range 15 to 300°K, and the thermodynamic functions have been calculated. Dysprosium had previously been found to exhibit two magnetic transitions and corresponding to these we have observed two maxima in the heat capacity, one at 174°K and a second at 83.5°K. Only the lower peak shows a dependence on the thermal history of the sample and this dependence was investigated. A correlation of the various contributions to the entropy at room temperature indicates that the magnetic contribution is R ln (2J+1). The value of S0298.16 is 17.87 cal (°K)—1 (g atom)—1.
Corresponding States Treatment of Nonelectrolyte Solutions
Authors: Scott Robert L.
Published: January 2005

Recent theories of solutions (Prigogine and co-workers; Salsburg and Kirkwood) use a theory of corresponding states to deduce the properties of solutions from theoretically derived properties of the pure components (e.g., from the Lennard-Jones and Devonshire ``free volume'' or ``cell'' model). A characteristic of these theories is that they predict for molecules of the same size and dispersion force interactions a negative volume change on mixing.

Since the ``cell'' model gives very poor agreement with experimental data on energy-volume and volume-temperature relations of pure liquids, a corresponding states treatment has been carried through using an experimental equation of state for the pure liquid. If one assumes two kinds of ``cells'' in the mixture, a type for each of the components, the results agree with experimental data on solutions at least as well as previous theories. As before, contraction on mixing is found for a certain class of dispersion force solutions.

In any corresponding states treatment, the entropy of mixing will not be ideal either at constant pressure or at constant volume.
Influence of Molecular Electric Quadrupole Moments on Dielectric Constants
Authors: Zwanzig Robert W.
Published: January 2005

The effect of a molecular electric quadrupole moment on the dielectric constant of a gas composed of nonpolar molecules is calculated to the lowest order of density and polarizability in which it appears. The quadrupoles induce electric dipoles in neighboring molecules, and these dipoles interact with an applied uniform electric field. The total effect is a deviation from the Clausius-Mosotti equation, proportional to the square of the quadrupole moment, and of the same order of magnitude as the deviation due to fluctuations in dipole moment calculated by Kirkwood, and the deviation due to the variation of polarizability with density calculated by Mazur and Jansen. The theory is tested by calculating the quadrupole moment of CO2 from dielectric constant data. The result is about five times larger than the value obtained by microwave pressure broadening, and is about forty percent larger than the value obtained by Pople from the second virial coefficient of CO2.
Dipole Moment of the HCN Molecule
Authors: Iguchi Kaoru
Published: January 2005

π-electronic and σ-electronic energy levels of the HCN molecule are calculated by the LCAO method with full inclusion of configuration interaction.

Slater atomic orbitals with effective charge Z=3.180 for the carbon atom and 3.850 for the nitrogen atom are employed. The C–H distance is assumed to be 1.09 A and the C–N distance 1.15 A. The value 2.664 Debye units is obtained for the dipole moment of the molecule in the ground state, while the experimental value is 2.766 Debye units.
Improved Free-Volume Theory of Liquids. I
Authors: Dahler John S. , Hirschfelder Joseph O. , Thacher Henry C.
Published: January 2005

To obtain practical results from the cell theories of liquids, it seems necessary to assume a simple symmetry for the distribution of a molecule about its lattice site. This is accomplished by replacing the interaction of the molecule with its neighbors by some ``suitably averaged'' interaction. In the Lennard-Jones and Devonshire treatment, the pair interaction is replaced by its spatial average. We find that a Boltzmann-type average is much more satisfactory. For an assumed symmetry of the distribution, our procedure provides an extension of Kirkwood's theory such that the resulting integral equation for the distribution function can be solved by numerical methods.

The introduction of the Boltzmann-type averaging provides a pair wise correlation between the motions of molecules in neighboring cells. These correlative effects have been neglected in previous cell theories of the liquid phase. Numerical calculations of the equation of state and thermodynamical properties are, at present, being carried out.

In evaluating the integrals which arise in this development, we have found the function L0 defined by the double surface integral ∫ ∫ f(r12,r1,r2,R)dω1dω2⧸ ∫ ∫ dω1dω2 =1R ∫ r12(min)r12(max)f(r12,r1,r2,R)L0(r1/R,r2/R,r12/R)dr12to be extremely useful. Here, r1 and r2 are the radii of two spheres, R the separation of their centers, r12 the separation of points on the two spheres, and f an arbitrary integrable function of r12/R. L0 is found to be a quadratic function of r12, different for various subranges of the interval [r12(max), r12(min)]. For a variety of physical problems such as x-ray and electron diffraction, L0 may have application.
Interpretation of the Kinetics of Mercury Alkyl Pyrolysis
Authors: Pritchard H. O.
Published: January 2005

The high frequency factors observed for the thermal decomposition of some mercury dialkyls are shown to be consistent with the hypothesis that the primary step is a fission into three fragments rather than two; this mechanism is possible because of an almost unique thermochemical property of the mercury alkyl system and, within the limitations of the simple approximation used, is not incompatible with the concept of localization of activation energy within the critical bonds.
Infrared Spectrum of Hydrogen Fluoride
Authors: Kuipers G. A. , Smith D. F. , Nielsen A. H.
Published: January 2005

The infrared vibration-rotation spectrum of HF has been re-examined out through J=11 for the fundamental, and through J=8 for the first overtone. Five lines of the pure rotational spectrum of HF (J=10, 11, 12, 14, 15) have been observed in absorption and emission between 15 and 24 μ. Extension of the measurement to larger J values makes it possible to observe the effect of the term HvJ3(J+1)3 in the energy, and to obtain Hv. With the new data the molecular constants have been re-evaluated by IBM machine. These constants when used with the energy expression permit accurate prediction of the observed energy levels.
Periodic Precipitation
Authors: Prager Stephen
Published: January 2005

The phenomenon of periodic precipitation has been subjected to calculations based on the diffusion-plus-supersaturation model first proposed by Ostwald. The mathematical difficulty caused by an infinite density of Liesegang rings at the original junction between the two solutions is avoided by the introduction of a thin ``clear'' zone which is supposed to be initially free of reactants. A further simplification results from assuming that one of the reactants is present in considerable excess, so that its diffusion remains essentially unaffected by the precipitation. Calculations show that the ratio between the distances from the initial boundary of two successive rings rapidly approaches a constant value, in agreement with experiment. Results have been obtained for the case where both reactants have the same diffusion coefficient.
Some Physical Properties of Pure Liquid Ozone and Ozone-Oxygen Mixtures
Authors: Jenkins A. C. , DiPaolo F. S.
Published: January 2005

The melting point of pure liquid ozone has been determined by two methods and found to be —192.5±0.4°C. The surface tension of pure ozone at —182.7°C is 38.1±0.2 dynes/cm. Densities of pure liquid ozone are as follows: 1.5727±0.0004 g/cm3 at —182.9°C, 1.5839±0.0011 g/cm3 at —185.6°C, and 1.6130±0.0004 at —195.6°C, the last value being for the super-cooled liquid. The viscosity of pure liquid ozone is 1.56±0.2 centipoises at —183.0°C and 4.14±0.5 centipoises for the supercooled liquid at —195.6°C.

Densities of several liquid ozone-oxygen mixtures have been measured. These measurements show that densities of liquid mixtures can be calculated accurately from densities of pure oxygen and ozone by the relation 1/d = x1/d1+x2/d2, where d is the density of the mixture, d1 and d2 are the densities, and x1 and x2 the weight fractions of pure oxygen and pure ozone, respectively, at the given temperature.

Viscosities of ozone oxygen mixtures have been measured at —183.0°C and can be reproduced with an average deviation of 5% by the relation log10η=x1 log10η1+x2 log10η2, where η represents the viscosity of the mixture, η1 the viscosity of liquid oxygen, η2 the viscosity of liquid ozone, and x1 and x2 are the mole fractions of oxygen and ozone, respectively, all at the same temperature.
Surface Tension of Ionic Solutions
Authors: Buff Frank P. , Stillinger Frank H.
Published: January 2005

As an illustration of the molecular theory of surface regions, the singlet and pair distribution functions are evaluated for very dilute ionic solutions. When they are substituted into the statistical mechanical formulas for surface tension, expressions are obtained for the increase in surface tension over that of the pure solvent. The results of the theory are in better agreement with experiment than the earlier calculation of Onsager and Samaras, which was based on integration of the Gibbs adsorption equation. Finally, the distribution function approach is simply related to Mayer's recent virial coefficient theory for strong electrolyte solutions.
Vibrational Spectra of Formyl Fluoride and d-Formyl Fluoride
Authors: Morgan H. W. , Staats P. A. , Goldstein J. H.
Published: January 2005

The vibrational spectra of HCOF and of DCOF have been examined in the gas and solid phases by infrared techniques and in the liquid phase through the Raman effect. Of the six expected fundamentals for a molecule of point group C8, frequencies have been assigned to the five planar vibrations and a tentative assignment made for the nonplanar vibration. A normal coordinate analysis was applied to the A′ vibrations of HCOF, neglecting all interaction terms, and a set of force constants obtained which predict reasonably well the isotopic shifts in DCOF.
Mass Spectrometer Study of the Vapors from Red Phosphorus and Arsenic
Authors: Kane J. S. , Reynolds J. H.
Published: January 2005

The subliming vapors from red phosphorus and arsenic have been subjected to electron bombardment and the mass spectra studied over a range of electron energies, orifice sizes, and crucible temperatures. Detailed appearance potential curves of the monomer, dimer, trimer, and tetramer ions are presented. The relative mass spectra did not change with orifice size or crucible temperature. The hypothesis of essentially complete sublimation as the tetramer is advanced and defended. Concurrent studies of the rate of sublimation under Langmuir conditions versus temperature lead to heats of activation for the sublimation process which are in satisfactory agreement with earlier weight loss studies. Influence on the mass spectrum by thermal dissociation at the mass spectrometer filament was studied by increasing the area of glowing tungsten in the ion source. Analysis of changes in the appearance potential curves so produced reveals structure in these curves not detectable directly. A search for heavy ions failed to detect P8+ ions in the abundance reported earlier but detected As6+ and As8+ ions with an abundance about 10—5 as great as As4+.
Ionization on Platinum and Tungsten Surfaces. I. The Alkali Metals
Authors: Datz Sheldon , Taylor Ellison H.
Published: January 2005

The ionization of all of the alkali metals on tungsten and on tungsten oxide surfaces follows the Saha-Langmuir equation with no reflection. On platinum, however, a departure from this equation indicates partial reflection of the atoms. The reflection of Na is probably 0%, since the ionization efficiency is given closely by the Saha-Langmuir equation with a value of 5.50 ev for the work function of Pt at 2000°K. The same value of the work function then indicates reflections of 18% for Li, 48% for K, 22% for Rb, and 8% for Cs, at 2000°K.
Dielectric Properties of Wool-Water Systems. II. 26 000 Megacycles
Authors: Windle J. J. , Shaw T. M.
Published: January 2005

The complex dielectric constant for wool-water systems has been determined at a frequency of 26 000 Mc by a cavity resonator method similar to the method employed at 3000 and 9300 Mc. At 26 000 Mc, measurements on single wool fibers and at relative humidities as high as 98% have proved feasible.

The complex dielectric constant of the wool-water system increases with increasing water content. Curves for the dielectric constant and loss factor of the wool-water systems at 26 000 Mc are presented and analyzed in terms of a new theory of water sorption by wool. According to this theory, which is based upon a theory originally proposed by Cassie, the water sorbed by wool consists of three distinct molecular species: (1) localized water irrotationally bound to polar sites in the wool, (2) mobile water with bulk liquid properties, and (3) intermediate water with a potential energy of absorption which lies between those for localized and mobile water. The analysis of the measurements at 26 000 Mc for the higher relative humidities in terms of this theory has resulted in a more thorough description of the properties of the sorbed water than was possible for the data obtained at 3000 and 9300 Mc.
Emission Band Spectra of Nitrogen. The Fifth Positive System
Authors: Lofthus Alf
Published: January 2005

19 bands of the fifth positive system of nitrogen have been photographed in the second and third orders of a 21-foot grating spectrograph. Vibrational and rotational analyses gave the following results: (1) x 1Σg− state: Be=1.750, αe=0.0225, De=6×10−6, Te=a′+45284.7, ωe=1910, ωexe=20.7, re=1.168 A. (2) a′1Σu− state: Be=1.480, αe=0.0164, De=6×10−6, Te=a′, ωe=1530, ωexe=12.0, ωeye=0.033, re=1.270 A. An anomalous intensity distribution in the v′=0 bands was observed.
Observed n→π Bands in the Ultraviolet Absorption Solution Spectra of the Di-aza-naphthalenes
Authors: Hirt R. C. , King F. T. , Cavagnol J. C.
Published: January 2005

Weak bands have been observed in the ultraviolet absorption solution spectra of phthalazine, quinoxaline, 6-chloroquinoxaline, and 6-bromoquinoxaline, which show ``blue-shifts'' in a more polar solvent sequence. They, along with similar reported bands in cinnoline, have been assigned as n→π* bands analogous to those of the diazines and triazines.
Interatomic Potential Functions of Sodium and Potassium
Authors: Ling Rufus C.
Published: January 2005

The liquid structure theory of Born and Green is used to interpret x-ray diffraction measurements on liquid sodium and potassium to find an effective interatomic potential function for pairs of sodium and pairs of potassium atoms. This potential function predicts approximately the correct binding energy for solid sodium and potassium, and when reinserted in the x-ray formulas predicts scattering curves at higher temperatures which are in good agreement with experiments.
Soft X-Ray Absorption Edges of Metal Ions in Complexes. II. Cu K Edge in Some Cupric Complexes
Authors: Cotton F. Albert , Hanson Harold P.
Published: January 2005

It is shown that the crystal field splitting of the 4p orbitals of Cu(II) in some complexes can be correlated with the splitting of the 1s—4p transition observed in studies of the K absorption edges of these complexes, provided the ligand-metal bonding is not appreciably covalent.
Scattering of High Velocity Neutral Particles. IX. Ne–A; A–Ne
Authors: Amdur I. , Mason E. A.
Published: January 2005

Total collision cross sections have been measured for neon atoms with energies between 500 and 2100 ev, scattered in room temperature argon, and for argon atoms with the same energies scattered in room-temperature neon. The experimental results have been analyzed to obtain the following potential energy of interaction between a neon atom and an argon atom: V(r)=1.01×10−9/r9.18 erg,for r between 1.91 A and 2.44 A.

This potential is in agreement with one obtained by a simple combination of the potential between two neon atoms with that between two argon atoms. It is also consistent with the potential, valid at larger separation distances, which has been derived from measurements of gaseous compressibility, viscosity, and crystal properties.
Distribution Coefficient of Boron in Germanium
Authors: Bridgers Henry E. , Kolb E. D.
Published: January 2005

The effective distribution coefficient of boron in germanium has been measured as a function of crystal growth rate. Its behavior is shown to agree with that predicted by the theory of Burton et al. for a solute whose equilibrium distribution coefficient is greater than unity. The coefficient decreases rapidly with increasing growth rate from its equilibrium value 17.4 to 2.2 at a growth rate of 10—2 cm/sec.
Thermodynamical Fundamental Equation for Spherical Interface
Authors: Kondo Sohei
Published: January 2005

The relation between the radius of the Gibbs dividing surface and the superficial density is investigated in detail and the generalized Kelvin relation is obtained. Consequently the fundamental equation for spherical interface is expressed by dE=TdS+μdN−pαdVα−pβdVβ+γdA+(∂γ/∂a)Ada. The generalized Kelvin relation is the explicit differential equation for determining the location of the surface of tension which does not contradict with the conventional one. Thus the mathematical formalism of thermodynamics will be completed for treating spherical interface in a rigorous and self-consistent manner, the last ambiguous point being eliminated from the conventional Gibbs treatments.
Vacuum Ultraviolet Photochemistry. Part IV. NO at 1236 A
Authors: Zelikoff Murray , Aschenbrand Leonard M.
Published: January 2005

Dissociative recombination of NO+ ions with electrons was shown to take place when NO is irradiated with krypton resonance radiation at 1236 A. Application of a dc voltage across the reaction cell produces an increased rate of decomposition by electron or positive ion bombardment of neutral NO molecules.
Application of Cell Theory to Liquid Hydrocarbons
Authors: Simha Robert , Hadden Stuart T.
Published: January 2005

The cell theory in the formulation of Prigogine, Trappeniers, and Mathot and their assumptions are examined. The molecular volumes of n-paraffins of high molecular weight are well represented in terms of an energy and volume parameter characteristic of the repeating unit. Fairly good agreement for branched systems is also found on making the proper modifications in the equation of state. The resulting low temperature heats of vaporization seem reasonable. One can show that the theory leads to the Kurtz-Lipkin-Sankin relations and interprets, so far, for paraffins their K1 and K5. Isotherms up to about 1000 bars can be represented fairly satisfactorily, 80–90% of the total compression observed being accounted for. This applies to n-paraffins as well as polyethylene and, in a semiempirical manner, to polystyrene. The physical significance of the constants in the empirical Tait equation is explored. For large chain lengths C is a pure numeric and independent of structure and molecular weight, in qualitative conformity with experimental results. B is related to the ratio of characteristic energy and volume of the submolecule, or to the above parameter K1. These results argue in favor of extending the theory, so as to permit handling of a wider range of variables, and other types of molecules.
Effect of Anisotropic Hyperfine Interactions on Paramagnetic Relaxation in Liquids
Authors: McConnell Harden M.
Published: January 2005

A simple ``microcrystalline model'' is developed to discuss the effect of molecular motion in the liquid state on the paramagnetic relaxation of ions or molecules with spin S = ½. This theory relates the paramagnetic relaxation times T1 and T2′ to the anisotropy in g, Δg = gII — g⊥, to the anisotropy in the nuclear hyperfine interaction, A–B, and to the correlation time τc which describes the Brownian tumbling motion of the microcrystal in the liquid state. The contribution of the anisotropic hyperfine interaction to the paramagnetic relaxation turns out to depend on the nuclear spin quantum number Iz, so that different hyperfine multiplets in a paramagnetic resonance spectrum can show different line widths.
Microwave Spectrum and Molecular Constants of Nitrosyl Bromide
Authors: Weatherly T. L. , Williams Quitman
Published: January 2005

The microwave spectrum of NOBr has been studied in the region 20 000 to 40 000 Mc/sec and an analysis made of the J = 2→3 transition. The following molecular constants were obtained. NOBr79NOBr81Rotational constants (Mc/sec)A83 34083 340B3747.243722.49C3586.003563.34Asymmetry parameterb−0.001012−0.000998Quadrupole coupling components (Mc/sec)χaa  388.3  325.5χbb−239.5−200.2χcc−148.8−125.3The structural parameters obtained from these are d(N–O) = 1.15 A, d(N–Br) = 2.14 A, d(O–Br) = 2.81 A, and ∠Br–N–O = 114°. The interatomic distances are compared with electron diffraction results, and a brief interpretation of the quadrupole coupling in terms of chemical bonds is given.
Surface Diffusion and Thermal Transpiration in Fine Tubes and Pores
Authors: Hill Terrell L.
Published: January 2005

The role of surface transport in the passage of a gas at low pressure through fine tubes or pores is examined in terms of simple models of mobile and localized adsorption. The amount of surface transport becomes about equal to the amount of gas transport when the tubes or pores have radii of the order of several hundred Angstrom units. The theory predicts that surface transport will have little effect on the pressure gradient across the tube or pores in the absence of a temperature gradient. But the pressure gradient should be increased considerably, as a result of surface transport, over the usual (thermal transpiration) pressure gradient when there is a temperature gradient across the tube or pores.
Proton Positions in Brucite Crystals
Authors: Elleman Daniel D. , Williams Dudley
Published: January 2005

The proton positions in brucite have been determined by comparison of nuclear magnetic resonance spectra with existing x-ray data. The protons are located in parallel planes, in each of which the protons are arranged in a pattern having hexagonal symmetry. The distance between adjacent protons in a given plane is 3.12±0.01 A, while the distance between a given proton and its nearest neighbors in the next plane is 1.93±0.02 A. The distance between adjacent proton planes is 0.69±0.02 A. The internuclear distance in the OH bond is found to be 0.98±0.02 A.
Electronic Spectra of Polyacetylenes
Authors: Beer Michael
Published: January 2005

The low-temperature emission spectra in rigid glass solutions of several substituted polyacetyelnes have been investigated. All the compounds phosphoresced with decay lifetimes ranging from 0.01 to 0.3 second. None of the compounds with less than four triple bonds fluoresced except diphenyl acetylene. All compounds with four triple bonds did fluoresce. An explanation is offered for this phenomenon. Some new absorption measurements were made on dimethyl diacetylene, dimethyl triacetylene, and dimethyl tetraacetylene. The polarization of the transition between 32 000 and 40 000 cm—1 in a single crystal of dimethyl triacetylene was found to be along the axis of the molecules. These results and those of previous investigators show that the energy level arrays of the molecules can be related and that they vary systematically as the number of triple bonds increases. This is in accord with expectation on the basis of simple molecular orbital theory.

An assignment of the symmetries of the electronic wave functions is proposed on the basis of the positions and intensities of the bands.
Work Function and Electrical Conductivity of Hydrogen Covered Nickel Films. The Effect of Contamination
Authors: Sachtler W. M. H.
Published: January 2005

Hydrogen was adsorbed on evaporated nickel films, and the change in electric conductivity and photoelectric emissivity was investigated. It was found that hydrogen adsorption on extremely clean nickel surfaces causes an immediate decrease in conductivity and an increase in work function. On contaminated films, however, the adsorption is slow and its effects on conductivity and work function are of opposite sign; i.e., work function is decreased and conductivity is increased.
Electronic States and Potential Energy Diagram of the Iodine Molecule
Authors: Mathieson Lois , Rees A. L. G.
Published: January 2005

The existing spectroscopic data on the iodine molecule have been reanalyzed, some new assignments proposed, and a potential energy diagram computed for some ten electronic states up to 55 000 cm−1. In particular, the following new assignments have been made for the upper levels of certain absorption bands—(1) a repulsive Σu+3(0u−) to the weak absorption at λ2700 in iodine vapor, (2) an ionic Σu−3(0u+) to the PRKM and Skorko band systems, and (3) a state arising from the mixing of a homopolar Π0+3(0u+u) and an ionic Σu+1(0u+) to the Cordes bands. In addition, the λ3416 and λ4300 ``continua'' have each been interpreted satisfactorily as a region of unresolved, overlapping bands with a lower limiting frequency. Other states lying in the region 40 000–55 000 cm−1 have been established.

New methods have been used to deduce segments of upper state potential energy curves.
Effect of Crystal Structure upon the Luminescence of Manganese-Activated Lithium Titanate
Authors: Lorenz M. R. , Prener J. S.
Published: January 2005

At —195°C, the photoluminescence spectrum of Li2TiO3: Mn phosphors has been found to consist of nine narrow bands in the red. This is typical of phosphors activated by Mn+4 ions. The phosphorescence at —195°C decays exponentially with a lifetime of 1.1 milliseconds. Disordering of the cation arrangement in the Li2TiO3 structure by addition of MgO or heat treatment results in a disappearance of the fine structure in the emission and its replacement by a single broad band. The phosphorescence consists of a number of faster superimposed exponential decays. These results are interpreted qualitatively in terms of the changes in interaction of the states of the Mn+4 ion with the crystal.
Equation of State of Water on the Thomas-Fermi Model
Authors: Latter A. , Latter R.
Published: January 2005

Two methods are described for extending the Thomas-Fermi model of a compressed atom to molecules containing two types of atoms. The methods are applied to H2O at zero temperature to determine pressure and internal energy as functions of the density, the position of the protons relative to the oxygen nucleus, and the electrostatic potential distribution within the molecule.
Microwave Spectrum of NO2: A Rigid Rotor Analysis
Authors: Bird George R.
Published: January 2005

Four new rotational lines, each of these divided into a multiplet by magnetic interactions, have been observed in the microwave spectrum of N14O216, bringing the total number of observed lines to five. A rigid rotor analysis has been performed to identify four of these, and probably the fifth. This new analysis removes the disagreement between McAfee's microwave assignment and Moore's infrared results, and explains the absence of N15O2 lines in the region search by Muller. Molecular parameters obtained are: angle ONO = 134° 15′, rN–O = 1.197 A. A combination rule for magnetic fine structure spacings is discussed. General conclusions are drawn regarding future investigations of asymmetric rotor free radicals.
Infrared Spectra of Polymers. I. Effect of Crystallinity on the Infrared Spectrum of Polyethylene and on the Infrared Spectra of Nylon 6 and Nylon 11
Authors: Tobin Marvin C. , Carrano Matthew J.
Published: January 2005

The melt and polarization spectra of dotriacontane and polyethylene in the 750–1500 cm—1 region and of nylon 6 and nylon 11 in the 450–4000 cm—1 region are presented. In addition, the melt and crystal spectra of stearone are presented in the 650–3500 cm—1 region. The effect of crystallinity on the spectrum of polyethylene is discussed. With the aid of published Raman spectra of crystalline hydrocarbons, an assignment of frequencies for polyethylene is made. The effect of crystallization on the spectrum of stearone is discussed and unusual features pointed out.

Orientations in films of nylon 6 and nylon 11 are shown to be in the extrusion direction. The effect of melting on the hydrogen bonding and on the CO and NH frequencies is discussed. A partial assignment and classification of frequencies is made. When the films are melted, certain peaks vanish. These are ascribed to splitting arising from crystal forces.
Infrared Spectrum and Structure of the Thiocyanate Ion
Authors: Jones Llewellyn H.
Published: January 2005

The infrared absorption spectra of aqueous and solid KNCS have been studied (the latter in detail) from 280–10 000 cm—1. The fundamental frequencies of NCS— in aqueous solution are v1 = 2066, v2 = 470, and v3 = 743 cm—1. In the solid, the degeneracy of the bending vibration is removed and four fundamentals are observed at 2053, 484, 470, and 749 cm—1, respectively. Many combination bands were observed for solid KNCS from which the anharmonicity constants and the frequencies for infinitesimal amplitudes of vibration were calculated. The fundamental frequencies of the C13 and S34 isotopic species were observed also. From the zero-order frequencies, force constants were calculated for NCS— in KNCS as kN–C = 15.95 md/A, kC–S = 5.18 md/A, k12 = +0.9 md/A, and kα/RC–NRC–S = 0.311 and 0.300 md/A. With the use of Badger's rule the bond distances are calculated to be RN–C = 1.17 A, RC–S = 1.61 A. These distances indicate a considerable amount of double bond character in the C–S bond.