bluuebunny/crossref_metadata_2025 huggingface dataset:
A Reduced Equation of State for Gases and Liquids
Authors: Benson Sidney W. , Golding Robert A.
Published: January 2005

An empirical, reduced equation of state is presented which holds with reasonable accuracy for both liquids and gases. Liquid densities of non-associated substances are predicted to within 4 percent, vapor pressures to within 25 percent, heats of vaporization to within 10 percent and gas isotherms reproduced to within 10 percent. The values predicted for the coefficients of thermal expansion and compressibility are not better than 30 percent. With the exception of the latter which are incapable of good representation by any such reduced equation, the equation represents a marked improvement over the van der Waals and Berthelot equations.
Experimental Determination of Even-Odd Character of Excited Electronic States of Molecules with a Center of Symmetry
Authors: Platt John R.
Published: January 2005

Even-even transition intensities increase with monosubstitution but decrease with opposed disubstitution. Even-odd transition intensities which increase with monosubstitution must increase further with opposed disubstitution.

Determination of parity in this way may settle disputed assignments. Thus the 1A1g—1E2g π-transition of benzene is probably at 1700 A. The first singlet absorption of naphthalene is 1A1g—1B1u or 1A1g—1B2u and cannot be 1A1g—1A1g even though the cancellation of transition matrix elements (from configuration interaction, in the one-electron approximation) gives it an intensity and vibrational structure similar to those in a forbidden transition. The visible bands of porphine are even-odd (a2u→eg 1Ag—1Qu0).

Intensities in the 2100 A transition of phenyl derivatives are being remeasured to settle its assignment in benzene, since existing data give conflicting results.
Statistical Thermodynamics of Rubber Elasticity
Authors: Wall Frederick T. , Flory Paul J.
Published: January 2005

Two principal differences between the theories of rubber elasticity advanced by James and Guth and by other authors are examined in the light of certain fundamental concepts. First the distribution functions for molecular chain lengths in vulcanized rubber networks are considered from the point of view of symmetry. Assuming a relaxed network to be isotropic and a network subject to uniform stress in one direction to be transversely isotropic, it is possible to formulate very general mathematical forms with respect to which the actual distribution functions must be compatible. It is shown that the functions employed by Wall and by Flory and Rehner are consistent with the required general forms; those of James and Guth are incompatible with any degree of isotropy and suggest an aeolotropic structure for vulcanized rubber.

It is also shown that the configurational entropy of vulcanization must be zero and quite independent of the statistical nature of the chains comprising the network, providing the network is not deformed macroscopically. The negative entropy of vulcanization derived by James and Guth arises from their erroneous identification of the configurational probability with the number of configurations which a microscopically specified network structure could assume, rather than with the total number of configurations for all network structures which are consistent with the requirements of the vulcanization process. The assertion of James and Guth that the configurations of the polymer chains are altered in some systematic manner by the introduction of cross-linkages and their concept of ``internal pressure'' originate in this error. The present article attempts to clarify the currently prevalent confusion with respect to rubber elasticity theory.
Magnetic Study of Some Inorganic Compounds of Arsenic, Antimony, and Bismuth
Authors: Prasad Mata , Kanekar C. R. , Mulay L. N.
Published: January 2005

In the graphs of the molecular susceptibilities χm of some salts of As, Sb, and Bi, containing the same anions against Z, the total number of electrons in them are nonlinear in each case if all the salts are taken into consideration. These graphs are, however, similar in nature and bring out the family relationship of these cations. Ikenmeyer's relation is seen to hold true only in the case of the halides of As, Sb, and Bi and the salts of these cations in combination with the same anion.

The linear relation observed between χm of the salts of As, Sb, and Bi containing the same anion and the number of electrons N in the cations has been used to evaluate the susceptibilities of the cations and the anions in combination with them. The significance of this relation and its advantages over other methods of determining ionic susceptibilities have been discussed. The experimental susceptibilities of these cations have been compared with the theoretical values calculated by Slater's and Angus' methods and have been used to evaluate the radii of the cations.
A Study of Two-Center Integrals Useful in Calculations on Molecular Structure. I
Authors: Roothaan C. C. J.
Published: January 2005

Convenient formulas have been obtained for the overlap integrals ∫χaχbdv, kinetic energy integrals —½∫χaΔχbdv, nuclear attraction integrals Z∫χa(1/ra)χbdv and Z∫χb(1/ra)χb′dv, and coulomb repulsion integrals ∫   ∫ χa(1)χb(2)(1/r12)χa′(1)χb′(2)dv1dv2, where χa, χa′, χb, χb′ are Slater-type AO's on the centers a and b. Explicit formulas are given for all the integrals arising from the principal quantum numbers 1 and 2, for arbitrary values of the effective nuclear charges and the interatomic distance.
A Study of Two-Center Integrals Useful in Calculations on Molecular Structure. II. The Two-Center Exchange Integrals
Authors: Rüdenberg Klaus
Published: January 2005

The problem of the two-center exchange integrals is solved in the most general way for Slater-type atomic orbitals with integral effective quantum numbers. No other restrictions are placed upon effective quantum numbers and effective nuclear charges, The integrals are expressed linearly in terms of certain auxiliary functions. A rule for finding the coefficients is given. The coefficients are explicitly computed for all cases involving orbitals with the quantum numbers 1, 2, and 3. The auxiliary functions are discussed in detail. The existing literature is reviewed, and a survey of present tables is made.
Internal Rotation in Ethylene Chlorhydrin
Authors: Mizushima San-ichiro , Shimanouchi Takehiko , Miyazawa Tatsuo , Abe Koo , Yasumi Masashi
Published: January 2005

The Raman and the infrared spectra of ethylene chlorhydrin have been remeasured with the result that the molecules take both the trans and the gauche forms in the gaseous and the liquid states, while they take only the gauche form in the solid state. By the measurement of the temperature dependence of the infrared absorption the energy difference between these two forms has been found as 0.95 kcal/mol.
The Infrared Dichroism of Diketopiperazine
Authors: Shimanouchi Takehiko , Kuratani Kenji , Mizushima San-ichiro
Published: January 2005

The absorption of polarized infrared radiations by diketopiperazine crystal has been measured in the wavelength region from 2.8 to 15μ. From the observed infrared dichroism the assignment of the absorption bands has been made.
Variation of Lattice Frequencies with Concentration in Molecular Mix-Crystals
Authors: Aggarwal Ram Ratan , Saksena B. D.
Published: January 2005

Assuming a unique linear periodic lattice for a non-ionic molecular mix-crystal, the lattice frequencies of the translational and rotational modes have been calculated for several concentration ratios of the two components. The observed variation in frequency in such crystals has been explained. The calculations also require that additional frequencies, not yet observed, should appear in Raman and infrared spectra.
Semilocalized Orbitals. I. The Hydrogen Molecule
Authors: Mueller Charles R. , Eyring Henry
Published: January 2005

Semilocalized orbitals are defined and applied to the hydrogen molecule. The basic criteria for the analytic form of this kind of orbital is that it shall assume either molecular or atomic orbital form for certain special values of the variational parameters. A binding energy of 4.20 ev is found in comparison with 3.60 and 3.76 ev obtained from the best molecular and atomic orbital calculations. The physical interpretation of the results is briefly discussed.
Semilocalized Orbitals. II. A Comparison of Atomic, Molecular, and Semilocalized Orbital Method for Diatomic Hydrogen Fluoride
Authors: Mueller Charles R.
Published: January 2005

In a previous paper the method of semilocalized orbitals was developed and applied to the hydrogen molecule. This method is applied to diatomic hydrogen fluoride simultaneously with atomic and molecular orbital calculation. In contrast to the results with the hydrogen molecule, the semilocalized orbitals are closer to molecular than atomic orbital form. The semilocalized orbitals give a much better binding energy than molecular orbitals and the improvement in dipole moment calculations is especially heartening. The results with the atomic orbital method are very discouraging.
A Comparative Study of Unpolarizable and Polarizable Metal-Solution Systems
Authors: MacGillavry D.
Published: January 2005

The properties of the metal-solution potentials of nickel in nickel free hydroxide and phosphate solutions are compared with the properties of unpolarizable electrodes and with the properties of polarizable metal-solution systems. The electrochemical equilibria of unpolarizable systems are analyzed in terms of transfer mechanisms between the phases present. In the absence of any electrochemical equilibria, the metal-solution potentials are interpreted as adsorption potentials. Chemisorption in the inner Helmholtz layer is discussed in connection with ``reversibility'' and polarizability of the system.
Lattice Theories of the Liquid State
Authors: Rowlinson J. S. , Curtiss C. F.
Published: January 2005

The assumptions underlying the lattice theory of liquids of Lennard-Jones and Devonshire are examined. Four modifications of this theory have been proposed which avoid some of these assumptions. These modifications are (a) by Cernuschi and Eyring, (b) by Ono, (c) by Peek and Hill, and (d) one suggested in this paper. It is shown that they may all be deduced as special cases of one mathematical treatment. They are intuitively more attractive than the original theory and avoid any mention of the so-called ``communal entropy.'' They give reasonable values of the second virial coefficient. None of them, though, shows much improvement over the original theory in calculating the critical constants and vapor pressure curves.
Infrared Studies of Mixed Crystals: Naphthalene in Anthracene
Authors: Pimentel George C.
Published: January 2005

Polarized infrared studies have been made using single crystals of dilute solid solutions of naphthalene in anthracene in the spectral region 755 to 830 cm−1. The ab plane at normal incidence was studied with the plane of polarization either parallel or perpendicular to the b axis. The mole fraction of naphthalene was varied from 0.009 to 0.029. The contour of the naphthalene band at 787 cm−1 shows a dependence upon concentration, approaching the contour observed in pure naphthalene. There is an increasing dichroic splitting of the band which is attributed to space group coupling as the number of nearest identical neighbors increases. It is likely that the magnitude of this splitting in naphthalene is only about 5–10 cm−1 and that the crystal forces in naphthalene as well as in the mixed crystals of naphthalene in anthracene are sufficiently weak that the ``oriented gas'' model is applicable. Using this model, the 787 cm−1 band of naphthalene is assigned as a single fundamental of either B1u or B3u class.
The Vibration Spectrum of Rutile
Authors: Matossi Frank
Published: January 2005

Raman effect data for rutile are evaluated for the force constants. It is shown that quasi-molecules TiO2 are formed with strong Ti–O bonds although every Ti atom is surrounded by 6 O atoms in about equal distances. The main force constants are (in 105 dynes/cm) 1.7 for the Ti–O bond of the quasi-molecules, 0.06 for the other Ti–O bonds, 0.2 for O–O bonds. The spectrum can be interpreted as that of coupled modified TiO2 molecules whose effective bond strength is a combination of the actual bond strengths.
Fourier Analysis of the X-Ray Scattering from Soap Solutions
Authors: Brady G. W.
Published: January 2005

A Fourier analysis of the x-ray diffraction of sodium dodecyl sulfate has been made on the basis that the micelles formed by aggregation of the long-chain molecules are spherical. The radial distribution of the micelles has been determined at two concentrations; the distribution functions show definite peaks indicating a preferred distance for neighboring micelles. It is concluded that the spherical micelle is compatible with the x-ray evidence. The deficiencies of the lamellar micelle are discussed.
Substituted Methanes. VII. Vibrational Spectra, Force Constants, and Calculated Thermodynamic Properties for CH3I and CD3I
Authors: Fenlon Paul F. , Cleveland Forrest F. , Meister Arnold G.
Published: January 2005

Raman displacements for the liquid, and infrared absorption wave numbers for both liquid and gas, have been obtained for CH3I, together with quantitative depolarization factors for the Raman lines and semiquantitative relative intensities for both the Raman and infrared bands. The present and previous data were critically compared, and probable values of the wave numbers corresponding to the fundamental vibrational frequencies were determined for both liquid and gaseous states. Force constants in a modified valence force potential function, containing all possible quadratic interaction constants, were calculated; these then were used to calculate the fundamentals of CD3I. Finally, the heat content, free energy, entropy, and heat capacity for both CH3I and CD3I were calculated for 11 temperatures from 200° to 1000°K, for the ideal gaseous state at 1 atmos pressure.
Ultrasonic Propagation in Binary Liquid Systems near Their Critical Solution Temperature
Authors: Chynoweth A. G. , Schneider W. G.
Published: January 2005

An investigation has been made on the propagation of ultrasonic waves (at 600 kc) through the critical solution temperature of two binary liquid systems; (1) aniline and n-hexane and (2) triethylamine and water. Results are given for the variation of the velocity with temperature. The behavior of the sound attenuation through the critical point is also shown. In both systems studied the attenuation exhibited a marked maximum at the critical solution temperature. A possible explanation of this effect is that the sound wave gives rise to configurational relaxation processes of greatly increased magnitude on account of the molecular clustering in the liquid system near its critical solution temperature.
The Microwave Spectrum of Methyl Stannane
Authors: Lide David R.
Published: January 2005

The microwave spectrum of methyl stannane between 25,500 and 29,000 mc is reported. All of the observed lines may be assigned to the J=1→2 rotational transitions of the isotopic species representing the five most abundant tin isotopes. The dipole moment was found from the Stark splitting to be 0.68±0.03 Debye unit. Insufficient information is available for a complete structure determination, but if tetrahedral angles and a C–H distance of 1.090A are assumed, the data can be fitted with a C–Sn distance of 2.143±0.002A and a Sn–H distance of 1.700±0.015A. The influence of hindered internal rotation on the spectrum is discussed.
The Electronic Energy Levels of Molecular Crystals
Authors: Winston Harvey
Published: January 2005

The electronic energy levels of a molecular crystal are classified according to representations of the space group of the crystal. When the ground state of the free molecule is totally symmetric, the number of crystal levels active in the absorption of light can be determined by a simple rule. Applications to rare earth crystal spectra and to the crystalline benzene spectrum are discussed.
Interpretation of the Vibration Spectrum of Mix-Crystals
Authors: Matossi Frank
Published: January 2005

The vibration frequencies of a linear chain of the type ...XZYZXZYZ... are calculated and discussed. The chain is considered to be a model for a mix-crystal of the components XZ and YZ. Only one vibration is strongly active enough to give a reflection band, its frequency being intermediate between those of the components, in agreement with observation. Another vibration, at lower frequencies, is very weak or inactive, depending on the exact nature of the mix-crystal structure—whether the ions X and Y are distributed regularly or statistically.
The Reactions of Methyl Radicals. II. The Abstraction of Hydrogen Atoms from Paraffins
Authors: Trotman-Dickenson A. F. , Birchard J. R. , Steacie E. W. R.
Published: January 2005

The reactions of methyl radicals formed by the photolysis of acetone and deutero-acetone with nine paraffins have been studied from 25°C to 340°C. If the combination of methyl radicals requires no activation energy, then the activation energies found for the abstraction of hydrogen atoms are as follows: ethane, 10.4; n-butane, 8.3; 2-methyl propane, 7.6; n-pentane, 8.1; 2,2-dimethyl propane, 10.0; n-hexane, 8.1; 2,3-dimethyl butane, 6.9 and 7.8; 2,3,4-trimethyl pentane, 7.9; 2,2,3,3-tetra-methyl butane, 9.5 (all values in kcal). The collision theory steric factors of these reactions are all less than 10−3.
The Mercury (3P1) Sensitized Decomposition of Normal and Iso-Butane at High Temperatures
Authors: Bywater S. , Steacie E. W. R.
Published: January 2005

The mercury (3P1) sensitized decomposition of normal and iso-butane at high temperatures is described. The reactions of both hydrocarbons result in the formation of decomposition products of butyl radicals at temperatures above 250°C. In the case of normal butane this reaction gives methane, ethane, ethylene, and propylene; and with iso-butane, only methane and butane. Activation energies are assigned to the various radical decomposition steps.
The Thermal Hydrogen-Oxygen Reaction at Relatively Low Temperatures
Authors: Broida H. P. , Oldenberg O.
Published: January 2005

In the behavior of the thermal hydrogen-oxygen reaction there is an apparent discrepancy. The second explosion of the thermal reaction occurs over a wide range of low temperatures down to 350°C, even though the rate of steady thermal reaction is very nearly zero. The authors used a criterion stated by Lewis and von Elbe to show that the same volume chain which explains the reaction at higher temperatures applies to the low temperature range. The inhibition period within the low pressure explosion region and the branching of the chains are briefly discussed.
Nuclear Spin Relaxation Studies in Dilute Sodium-Liquid Ammonia Solutions
Authors: Newman R. , Ogg R. A.
Published: January 2005

The nuclear spin relaxation times of the protons in dilute solutions of sodium in liquid ammonia have been measured at 30 Mc/sec over the room temperature-dry ice range. The data can be interpreted on the basis of an associative equilibrium existing between paramagnetic and diamagnetic solute species. This is in agreement with the results of the conventional magnetic susceptibility measurements. The paramagnetic component of the solutions seems to be about one-tenth as effective as a cupric ion in inducing nuclear relaxation.
Note on Orthogonal Atomic Orbitals
Authors: Slater J. C.
Published: January 2005

It is shown that orthogonal atomic orbitals, as introduced by Wannier for solid-state problems and by Löwdin for molecular problems, do not lead to a simple way of eliminating the non-orthogonality problem in the Heitler-London method. Thus, if a calculation of the H2 molecule is made using orthogonal atomic orbitals in place of ordinary atomic orbitals, proceeding by the simple Heitler-London method, the resulting diagonal energy of the lowest state shows no energy minimum. The orthogonal atomic orbitals are suitable for use, however, if we make a complete perturbation calculation, and for this purpose they are as convenient as LCAO's, but not appreciably superior.
Wall Reactions and Diffusion in Static and Flow Systems
Authors: Gomer Robert
Published: January 2005

The distribution of radicals at steady state has been computed for simple systems subject to heterogeneous and homogeneous reactions. Sample distributions are given. Expressions for two non-steady-state situations are derived for the case of a first-order gas and first- or second-order wall reaction. The effect of expansion and longitudinal diffusion on radical concentration in flow systems is discussed. Equations governing the former are derived and a method of estimating its effect rapidly is given. Expressions giving the upper limit of the latter are presented. It is shown that expansion may simulate a first-order reaction, and may be of considerable importance in fast flow.
Conductivities of Strong Electrolytes in Aqueous Solution
Authors: Evans Robert L.
Published: January 2005

The concentration dependence of the conductivities of strong electrolytes is of interest in both theory and application. Older theoretical and empirical equations fail at high concentrations.

This article presents three empirical equations for the concentration dependence of conductivity. The first of these contains only a single fitted parameter (``a'' in Eq. (1) and Table I). Each of the other equations contains two parameters and follows the experimental curves up to high concentrations. However, Eq. (3) is the only one that shows the proper exponential concentration dependence at very high concentrations.

Also, a description is given of two anomalies in the behavior of tetramethyl ammonium salts.
Fischer-Tropsch Reaction Mechanism Involving Stepwise Growth of Carbon Chain
Authors: Anderson R. B. , Friedel R. A. , Storch H. H.
Published: January 2005

Expressions are derived which predict satisfactorily the observed isomer and carbon number distribution of products from iron and cobalt catalysts in the Fischer-Tropsch synthesis. These expressions are based on three schemes of stepwise addition of one carbon atom to the end or adjacent-to-end carbons of the longest carbon chain of the growing group at the catalyst surface. The implications of these schemes to some general aspects of the reaction mechanism are considered.
The Mercury (3P1) Photo-Sensitized Reaction of Ethane at High Temperatures
Authors: Bywater S. , Steacie E. W. R.
Published: January 2005

The mercury photo-sensitized decomposition of ethane has been carried out with particular emphasis on the high temperature reaction. Evidence is given that under these experimental conditions the ethyl radical becomes unstable around 400°C. An activation energy of 39.5 kcal is assigned to the reaction C2H5=C2H4+Hon the basis of the proposed mechanism.
Influence of Foreign Gases at High Pressures on the Infrared Absorption Band of Methane at 3.3μ
Authors: Welsh H. L. , Pashler P. E. , Dunn A. F.
Published: January 2005

An infrared absorption cell for compressed gases was constructed and used at pressures up to 600 atmos. In the cell, which was of the reflection type, the length of the absorbing path could be changed from 5×10−4 cm to 4 cm by means of metal spacers placed between the window and the mirror. The influence of high pressures of helium, argon, and nitrogen on the intensity of the methane band at 3.3μ was investigated. It was found that the absolute absorption coefficient for the band increases linearly with the density of the foreign gas. With nitrogen at 600 atmos the absorption coefficient is 20 percent greater than that of the free methane molecule. The magnitudes of the coefficients of induced absorption are compatible with the assumption that the vibrating dipole of the absorbing molecule is increased by the reaction field of the polarizable foreign gas molecules in its neighborhood. The coefficient of absorption for the free molecule was found by extrapolating the measured coefficients to zero density of the foreign gas. The values derived from measurements with the three foreign gases agree closely, and give an average value of 1075×1010 sec−1 cm−1 at NTP.
Remarks on the Interpretation of the CH2 Vibrational Frequencies of n-Paraffins
Authors: Barrow Gordon M.
Published: January 2005

The infrared and Raman frequencies are calculated for the fundamental vibrations of an infinite n-paraffin chain. Valence force constants, chosen to give agreement between the calculated and observed infrared frequencies, give calculated Raman frequencies which are correlated with observed Raman lines. The difference in frequency to be expected for the Raman and infrared bands of the CH2 out-of-plane rocking vibration is discussed. The CH2 frequencies of propane are calculated from the infinite paraffin chain force constants and are compared with previous assignments.
LCAO Self-Consistent Field Calculation of the Ground State of Carbon Dioxide
Authors: Mulligan Joseph F.
Published: January 2005

LCAO molecular orbitals and ionization potentials have been calculated for the ground state of CO2 using Roothaan's LCAO self-consistent field method. The interactions of all electrons have been explicitly considered, and no extra-geometrical empirical data have been used. The calculated molecular orbitals are in general agreement with those predicted by Mulliken and Moffitt from semi-empirical considerations. The calculated ionization energies are 11.5 ev for a 1πg electron and 17.9 ev for a 2σu electron, compared with the experimental 13.8 ev, and 18.0 ev, respectively. The evaluation of the large number of integrals over atomic orbitals that occur, is discussed in an appendix. All the larger integrals were calculated exactly, the smaller ones approximated. Useful approximation methods for some of these integrals are considered.
Structural Model of Low Pressure ``Physical'' Adsorption
Authors: Cook Melvin A. , Pack Douglas H. , Oblad Alex G.
Published: January 2005

This article describes a proposed new type of adsorption potential associated with surface strain induced in the elimination of unbonded electron orbitals (``first-order strain''), and strain due to surface (chemical) heterogeneities, or surface impurities (``second-order strain''). These surface strains are assumed to give rise to a ``semi-chemical'' adsorbate-adsorbent attachment in the first layer of multimolecular films. This is termed ``structural adsorption'' and is considered to be largely responsible, along with ordinary van der Waal's potentials, for the low pressure region of the type II isotherm.

The theory is applied in the calculation of the adsorption isotherms for pure nitrogen, pure oxygen, and mixtures of nitrogen and oxygen on anatase. It is further applied in determining the composition of the adsorbate in mixed gas adsorption and in the computation of the surface pressure of these films over the entire range of relative pressures from zero to p/p0=1.0. Excellent agreement with experimental observations is achieved.
The Dielectric Constant of Water and the Saturation Effect
Authors: Booth F.
Published: January 2005

The Onsager and Kirkwood theories of polar dielectrics are extended to give expressions for the dielectric constant at high field strengths. The theory is applied in detail to water and simple formulas for the dielectric constant in terms of well-known quantities are obtained. The results of the calculation are embodied in the formula ε=n2+απN0(n2+2)μνEL(βμν(n2+2)EkT),where n is the optical refractive index, N0 the number of molecules per unit volume, μv the dipole moment of the water molecule, E is the field strength, and T the absolute temperature. L(x) is the usual Langevin function, and α and β are numerical factors which have the following values (a) Onsager method α=4/3, β=1/2.(b) Kirkwood method α=28/3√73, β=√73/6.From these formulas it is shown that the reduction of the dielectric constant due to the saturation effect is of importance for fields greater than 106 volts per cm.
The Stereochemistry of the Imidazolidine Ring
Authors: Fischer Ernst
Published: January 2005

The electric moments of several imidazolidine derivatives in p-xylene solution have been measured at various temperatures. It is suggested that the substances are mixtures of geometrical isomers which are in thermal equilibrium, the isomerism being due to the pyramidal arrangement of the valencies of the tervalent nitrogen.

From the temperature dependence of the moments, the energy difference between the two postulated isomers is calculated to be about 1.6 kcal/mole.
Infrared Spectra of CH2N2 and CD2N2
Authors: Crawford Bryce L. , Fletcher William H. , Ramsay D. A.
Published: January 2005

The infrared spectra of CH2N2 and CD2N2 have been investigated in the gas phase between 4500 and 400 cm−1 using a Perkin-Elmer spectrometer with LiF, NaCl, and KBr prisms.

The spectra have been correlated with a planar, nonlinear configuration for the diazomethane molecule with symmetry C2v. The perpendicular type bands for both molecules are all overlapped or perturbed by neighboring absorption bands, so that no accurate values for the least moments of inertia have been obtained.

Two alternative schemes of assignments for the vibrational frequencies have been proposed and the thermodynamic functions for CH2N2 computed.

Potential-function calculations have been carried out.
The Thickness of Shock Fronts in Argon and Nitrogen and Rotational Heat Capacity Lags
Authors: Greene E. F. , Cowan G. R. , Hornig D. F.
Published: January 2005

Shock front thicknesses in argon and nitrogen have been measured at Mach numbers of approximately 1.12, 1.28, and 1.40 by the reflectivity method. These thicknesses are significantly greater than predicted by Thomas and demonstrate the need for an improved theory which will cover the whole range of shock strengths. Reflectivity measurements have also been used to detect distortions of shock fronts in nitrogen owing to the lag of the rotational heat capacity. About 20 collisions are required for the rotational relaxation of nitrogen at room temperature.
Mobile Multilayer Adsorption of a Bose-Einstein Gas: Helium
Authors: Band William
Published: January 2005

The quantum properties of a Bose-Einstein gas give rise to a critical adsorption into a mobile film. If the energy of adsorption is assumed to decrease with thickness according to a simple power law, the theory gives an isotherm in good agreement with observations on helium adsorption at temperatures above the lambda-temperature of liquid helium, for all gas pressures higher than 10 percent saturation.

With mixtures of He3 and He4 isotopes the theory predicts appreciable adsorption of He3 only in the first or localized monolayer; all mobile monolayers should be practically pure He4 at all gas pressures. Comparison is suggested with the known isotopic constitution of the Rollin film below the lambda-temperature.
Optical Rotation of Quartz in the Infrared to 9.7μ
Authors: Gutowsky H. S.
Published: January 2005

The optical rotation of quartz has been observed in the infrared from 2.2 to 9.7μ. The measurements were made with a selenium film transmission polarizer and a similar analyzer; a Perkin-Elmer Model 12B infrared spectrometer was used as the monochromator and detector. Anomalous rotatory dispersion was found at wavelengths longer than 3.7μ. A tentative qualitative interpretation of the anomaly is suggested.
On the Distribution Function in Phase Space, with Application to the Statistical Theory of Liquids
Authors: Ikenberry Ernest
Published: January 2005

A simple form for the expansion of the distribution function in phase space, by means of modified hermite polynomials, is set up. Expressions for the density, temperature and the components of the mass current, of the strain tensor, and of the heat current, in terms of the coefficients in the expansion, are obtained. A simple method for obtaining the infinite set of integro-differential equations imposed upon the coefficients in the expansion of the distribution function by the Gibbs' principle of conservation of density-in-phase is outlined. Results obtained for the dissipative processes of heat conduction and of viscosity in liquids are summarized.
Calculated Thermochemical Properties for Hydrazine—Hydrogen Peroxide Reaction at High Pressures
Authors: Barr W. J. , Wilson E. Justin
Published: January 2005

A liquid bireactant system, consisting of a stoichiometric mixture of anhydrous hydrazine and hydrogen peroxide, is evaluated in terms of the resultant equilibrium temperature-pressure-density relationship corresponding to chamber pressures over the range 10,000 to 185,000 pounds per square inch. The analysis is based on the use of the reactants both at constant volume and at constant pressure, and data pertaining to the mole fractions of components of the product gas, its molecular weight and covolume are included for each case.
On the Interpretation of Relaxation Time Measurements in Gas Mixtures
Authors: Walker Richard A.
Published: January 2005

Most studies of the excitation of molecular vibrations in gas mixtures have been carried out using very low concentrations of the B type ``impurity'' gas to excite basic gas A. It is pointed out in this paper that such studies very likely fail to detect the possible importance of triple collisions of the AAB type. Indeed, data of Eucken and Aybar on mixtures containing quite high concentrations of B molecules is felt to furnish strong evidence for the triple collision excitation of COS molecules by argon and by nitrogen molecules.
Investigation of Turbulent Flames
Authors: Karlovitz Béla , Denniston D. W. , Wells F. E.
Published: January 2005

A new theory of turbulent burning velocity has been developed. Comparison of the predictions of the theory with turbulent burning-velocity measurements has led to recognition that the turbulent flame itself generates additional turbulence. A theory has been formulated to explain the production of turbulence by the turbulent flame, which permits calculation of the intensity of flame generated turbulence. A comparison of calculated maximum turbulence intensity values with the turbulence intensities that correspond to the measured turbulent burning-velocity data supports this theory.
A New Type of Short Wavelength Absorption Band in Alkali Halides Containing Color Centers
Authors: Delbecq Charles J. , Pringsheim Peter , Yuster Philip
Published: January 2005

Photo-chemically and additively colored potassium iodide crystals exhibit absorption bands in the ultraviolet which do not have the characteristic properties of V-bands. An interpretation of the origin of these bands is proposed.
Light Scattering Studies on Coiling Polyelectrolytes
Authors: Wall F. T. , Drenan J. W. , Hatfield M. R. , Painter C. L.
Published: January 2005

The molecular weight and size of polyacrylic acid in solution have been determined by measurement of light scattering. Use was made of Debye's 90° light scattering method employing two different wavelengths of light.

When the reciprocal specific scattering is plotted against concentration for homopolar polymers, a straight line is obtained which is readily extrapolated to zero concentration. Polyelectrolytes, however, are capable of ionizing in aqueous solution, thus becoming electrically charged by amounts depending upon the concentration. The electrostatic repulsion of the charges very probably affects the molecular size and gives rise to peculiar light scattering curves. By utilizing buffer solutions as solvents, the molecular size is held constant and the difficulties involved in the interpretation of scattering data are largely resolved.

The weight-average molecular weight of a certain sample of polyacrylic acid at pH values of 1.2, 3, 4, and 5 was found to be 206,000±10 percent. Molecular weight values at a particular pH using a specific buffer were reproducible to about ±3 percent. The remainder of the error was attributed to association of buffer ions with the charged polymer. The size of the particles in solution was found to be less than 550A in the low pH regions, with a definite tendency to increase at higher pH values. The slope of the straight line obtained when the reciprocal specific scattering was plotted against concentration was shown to be dependent upon pH. This dependence of slope may be related to particle size and shape.

In a non-ionizing solvent such as ethanol, the polymer exhibits scattering behavior typical of non-ionized polymers. The molecular weight of polyacrylic acid under these conditions was found to be 206,000, in agreement with values obtained in buffer solvents.
The Exchange of Water Between Hydrated Cations and Solvent
Authors: Hunt John P. , Taube Henry
Published: January 2005

The rate of exchange of water between the hydrated forms of Al+++, Cr+++, Fe+++, Ga+++, and Th+4 and the solvent water has been measured in solutions of varying acidity. With the exception of chromic ion, and of ferric ion at low acidity, the exchange is complete in ca 3 min at 25°. For chromic ion, the half-time for exchange is independent of acidity over a wide range and is ca 40 hr at 1 M salt concentration. The coordination number of chromic ion for water over the entire acidity range is 6.0. The initial hold-back of oxygen by ferric ion at low acid is slight and is attributed to the presence of polynuclear hydrolyzed species. For all the cations, the distribution of oxygen isotopes in the final solution is noticeably different from random, the cations showing a greater affinity for H2O18 over H2O16.

The rates of exchange are correlated with the electronic structure, which influences the energy required to form the transition state.
Macroscopic Space Charge in a Potassium Chloride Solution during Electrolysis
Authors: Schriever William , Ferguson Eldon E.
Published: January 2005

The macroscopic space charge and potential distributions were determined in a uniform column of 0.0024 N KCl solution during electrolysis by the methods used by Reed and Schriever. The platinum electrodes were 8×8 cm in area and spaced 40 cm apart; their constant potential difference was 8000 mv.

For the first time, all four space-charge regions were observed in one column of solution directly experimentally. The maximum negative space charge in the cathode region, 45×10−5 statcoulomb/cm3 at x=0.6 cm, and the maximum positive space charge in the anode region, 40×10−5 statcoulomb/cm3 at x=37.7 cm, both fell within the range of such space charges observed by Reed and Schriever.

The potential gradient between x=10 cm and x=35 cm had the constant value of 13.75 mv/mm. Thus, Ohm's law was obeyed in this region. The mean gradient in the first mm next to the cathode was 1130 mv/mm; that in the last mm next to the anode was 1200 mv/mm. The total fall of potential in these two one-mm layers was thus 29.1 percent of the total fall of potential between the electrodes. For Zn(C2H3O2)2 and CuSO4 the falls in these two layers were respectively only 1 and 1.06 percent of the total; the greatest value observed by Reed and Schriever was 22.5 percent of the total for NiSO4.

It is pointed out that the shapes of the potential distribution curves cannot be explained by phenomena which occur only at, and very near, the electrodes.
Directional Properties of Single Crystal of Anthracene Regarding Fluorescence Phenomena
Authors: Ganguly S. C. , Chaudhuri N. K.
Published: January 2005

The polarization of fluorescent radiation of single crystal of anthracene has been measured and this measurement has been utilized to determine the nature and orientation of oscillators. From this measurement it has been found that the oscillators are linear oscillators and their direction is independent of the direction of the electric vector of the incident light vibration. They make an angle of 33° with the b axis of the crystal.
Transformation of Water from Covalent to Electrovalent Combination in Formic Acid-Water Mixtures
Authors: Yang Tai-Yuan
Published: January 2005

It was shown by the author [J. Chem. Phys. 16, 865 (1948)] that water was necessarily a covalent compound, the molecule of which is formed by the neutralization of 2H+1+2θ+O+2; and its specific susceptibility, as we know, was −0.72 (corresponding to the molecular susceptibility −12.96) and that if it were an electrovalent compound its molecule should be formed by the neutralization of 2H+1+O−2, and its specific susceptibility would have been −0.625 (corresponding to the molecular susceptibility −11.25). (Susceptibility values have been multiplied by 106.)

In the present paper, we shall show that, in formic acid-water mixtures, part of the water depending on the weight of formic acid in the mixtures changes its specific susceptibility from −0.72 to −0.625. This indicates that this part of the water in the process of mixing transforms from a covalent to an electrovalent combination.
The Calculation of Coefficients of Coulomb and Exchange Integrals in Matrix Elements Involving Polar Singlet Structures
Authors: Simonetta Massimo , Schomaker Verner
Published: January 2005

Starting from Pauling's rules for calculating matrix elements for covalent structures, it is shown how to extend the valence-bond treatment to polar structures. Attention is called to the new types of integrals which are involved and simple procedures for evaluating their coefficients are described.
Magnetic Study of Some Hydrates of Boron Compounds
Authors: Prasad Mata , Kanekar C. R. , Kamat L. S.
Published: January 2005

Prasad and co-workers have recently established, from the measurements of the susceptibilities of a number of hydrated and anhydrous salts, that hydrates do not generally obey the additivity rule. Further, they have come to the interesting conclusion that the deviation from the additivity rule is closely connected with the number of molecules of water in the hydrate; in the case of several hydrates of the same salt, the departure from the additivity rule per molecule of water is highest for the hydrate containing the least number of molecules of water of crystallization and is least for the most stable hydrate. Boron is known to form several hydrated compounds. The polyborates are particularly interesting, since they can be dehydrated stepwise at suitable temperatures, and several intermediate hydrates can thus be prepared. The present paper deals with the study of the susceptibilities of the hydrated and anhydrous compounds containing boron and the examination of the applicability of the additivity law to hydrates.
Application of a Modified Quantum-Mechanical Cellular Method to the Hydrogen Molecule
Authors: Lewinson Victor A. , Kimball George E.
Published: January 2005

The application to molecules of the cellular method of Wigner, Seitz, and Slater has been tested by using it, in modified form, to calculate the electronic binding energy of the H2 molecule. The results are not better than those obtained by the Heitler-London and molecular-orbital methods, but they are good enough to suggest investigation of more complicated molecules, where the method may be more successful.
Near Ultraviolet Solution Spectra of the Diazines
Authors: Halverson Frederick , Hirt Robert C.
Published: January 2005

The near ultraviolet spectra of the diazines and various derivatives have been obtained in several solvents. Intensities, contours, and positions of the observed bands are combined with a valence-bond treatment of the diazine π-electrons to assign the transitions and to evaluate the C–C and C–N exchange integrals. The diazine band near 30,000 cm−1 (3333A) is assigned to a nonbonding nitrogen electron transition, and the band near 40,000 cm−1 (2500A) to a π-electron transition.
Triple-Dipole Interaction. I. Theory
Authors: Axilrod B. M.
Published: January 2005

Third-order perturbation theory is applied to the van der waals-type interaction between neutral atoms. An interaction between triplets of atoms results. The derivation of the third-order energy interaction W0′′′, is outlined, the procedure being somewhat similar to that used by London in his application of second-order perturbation theory to interatomic interaction. Since the perturbing potential is limited to the dipole-dipole term, the energy W0′′′ is called the triple-dipole interaction. The latter depends not only on the interatomic distances but also on the shape of the triangle formed by the three atoms; W0′′′ is positive for all acute and negative for most obtuse triangles.
Fractionation of the Carbon Isotopes in Decarboxylation Reactions. III. The Relative Rates of Decomposition of Carboxyl-C12 and -C13 Mesitoic Acids
Authors: Bothner-By Aksel A. , Bigeleisen Jacob
Published: January 2005

The relative rates of decarboxylation of C12- and C13-carboxyl mesitoic acids have been studied at 61.2 and 92.0°C. The ratios of the rate constants at these temperatures are 1.037±0.003 and 1.032±0.001, respectively. A comparison is made with similar ratios determined experimentally for other acids and with theoretical calculations of the ratios.
Substituted Stilbenes. II. Thermal Isomerization
Authors: Calvin Melvin , Alter H. Ward
Published: January 2005

The dependence of the rate of cis-trans isomerization on temperature has been determined for four para-substituted stilbenes. The rate parameters obtained are discussed relative to the theory of absolute reaction rates.
Quantitative Infrared Intensity Measurements. II. Studies on the First Overtone of Unpressurized CO
Authors: Penner S. S. , Weber D.
Published: January 2005

Quantitative infrared absorption measurements on unpressurized CO have been carried out for the first overtone in cells of different lengths and at different pressures of gas. The experimental data lead to a value for the integrated absorption of the first overtone of CO of 1.69 cm−2 atmos−1, which is in excellent agreement with results obtained previously from the study of mixtures of CO pressurized with infrared inert gases.
Transport Phenomena in Dense Media. II. Thermal Diffusion in Compressed Gases
Authors: Robb W. L. , Drickamer H. G.
Published: January 2005

From the thermodynamics of irreversible processes, values of the thermal diffusion ratio α have been calculated using (1) the virial equation of state, (2) generalized reduced enthalpies, (3) the Lennard-Jones and Devonshire ``cage'' model for liquids. These results are compared with experiment and with previously published calculations for a van der waals gas. Only the LJD model gave results markedly superior to van der Waals' equation. The LJD model predicts very large positive values of α for compressed liquids.
The Third Virial Coefficients of Polar Gases
Authors: Rowlinson J. S.
Published: January 2005

The third virial coefficient is calculated for a gas composed of spherical molecules whose intermolecular potential has a repulsive term proportional to r−12, an attractive term proportional to r−6, and which have point-dipoles at their centers. The calculated values are compared with the experimental results for steam and ammonia, using parameters previously calculated from the second virial coefficient. The agreement is good for ammonia but poor for steam. It is suggested that this is because of the neglect of the higher multipoles in the interaction potential.
The Stability of Gaseous Diatomic Oxides
Authors: Brewer Leo , Mastick Donald F.
Published: January 2005

The instabilities of FeO, NiO, MnO, and SiO2 upon vaporization, and upper limits to the heats of dissociation of these oxides and SiO have been determined by effusion experiments. The data available in the literature have been treated to obtain the heats of dissociation, or the upper limits thereof, of the gaseous oxides SnO, ZnO, CdO, CuO, PbO, GeO, and TiO.

The linear Birge-Sponer extrapolation of vibrational levels appears to give correct dissociation energies for the fourth-group oxides.