bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Reactions of Energetic Chlorine Atoms Produced by Neutron Capture in Liquid Systems
Authors: Miller J. M. , Dodson R. W. 
Published: January 2005

The fraction of the radioactive energetic chlorine atoms, formed by radiative neutron capture, that react with inactive carbon tetrachloride to give radioactive carbon tetrachloride, or with a solvent to give other radioactive organic halides, was studied as a function of composition in solutions of carbon tetrachloride in silicon tetrachloride, cyclohexane, and benzene. The reactions of similarly formed atoms were also studied for solutions of chlorine in cyclohexane and in benzene.
No significant effect of the temperature of the bombarded solution or of the energy of the neutrons was found.
The results are examined in terms of a theory which predicts the concentration dependence of some of the observed reactions, and alternative descriptions are suggested. It is concluded that the observed reactions occur before the recoil atoms are reduced to thermal equilibrium, and that particular reactions predominate in certain energy ranges.
Hydrogen Peroxide in the Thermal Hydrogen Oxygen Reaction. II. Reaction of Hydrogen Peroxide with Hydrogen and Chain Initiation in the Hydrogen Oxygen Reaction
Authors: McLane C. K. 
Published: January 2005

The reaction between hydrogen peroxide and hydrogen has been studied in the temperature range 470 to 500°C. The dependence of reaction rate on concentrations is rather complicated for hydrogen, and is between first and second order for hydrogen peroxide. The evidence presented favors the conclusion that the reaction proceeds by a chain mechanism involving no direct reaction between hydrogen and hydrogen peroxide molecules, at least at low hydrogen concentrations.
It was found that hydrogen oxygen mixtures undergo appreciable reaction at temperatures where the rate of reaction is normally very small if small amounts of hydrogen peroxide are first added.
On the Structure of a Catalyst Surface. II
Authors: Sips Robert 
Published: January 2005

Our previous results have been criticized by T. L. Hill on the ground that we considered energies of adsorption ranging from − ∞ to ∞. We have accordingly revised our former theory.
It appears that, if we assume localized adsorption without interaction, the possible mathematical forms for the adsorption isotherm are very limited. We have studied in detail, for the simplest of these, the distribution function for the adsorption energy. It turns out that this simplest isotherm is a generalization of both the Freundlich and the Langmuir isotherms.
Migration of Lithium and Several Multicharged Ions through Quartz Plates in an Electric Field. II
Authors: Gibson George , Vogel Richard C. 
Published: January 2005

The kinetics of the migration of lithium ions through crystalline quartz plates has been studied. The migration is induced by an electric field and probably takes place through tunnels inherent in the crystal structure and parallel to the principal axis of the quartz. It was shown that the rate-determining step is not the migration with in the quartz plate, but is some step associated with the passage of the lithium ions into or out of the quartz plate. A previous investigation showed that the migration within the quartz plate is the rate-determining step for sodium ions.
It was demonstrated that neither magnesium, zinc, cadmium, nor bismuth ions will migrate through quartz plates under our experimental conditions. Copper ions migrated through the quartz plates but caused the plate to crack in each experiment.
Molecular Orbital Predictions of Organic Spectra
Authors: Platt John R. 
Published: January 2005

The energies of the first two to five electronic transitions of 16 conjugated molecules are predicted as simple one-electron LCAO molecular orbital transitions (with overlap included). Assignments of the observed levels to the predicted levels are made. Qualitative agreement is good when S=0.25 and β=23,000 cm−1 for ring systems.
It is shown that configuration interaction must be introduced to modify these energy predictions and to account for the intensities in some molecules (``round-field'') such as benzene, triphenylene, coronene, and porphine. This interaction is less important in other molecules (``long-field'') such as pyrene, biphenyl, and tetrahydroporphine.
Empirical groupings of intensities and luminescence lifetimes are shown for the different singlet-singlet and singlet-triplet band types of round-field hydrocarbons and for related molecules containing conjugated hetero-atoms. The alteration of these groupings in long-field molecules, and under jj-coupling, is described.
Diffusion of Lead Chloride Dissolved in Solid Silver Chloride
Authors: Wagner Carl 
Published: January 2005

A particular solution of the differential equation of diffusion involving a diffusion coefficient proportional to concentration is presented.
From previous experiments by Wagner and Zimens the diffusion coefficient for the exchange of lead and silver ions, extrapolated to the concentration of a saturated solution of lead chloride in solid silver chloride, is calculated to be 2.4·10−9 cm2/sec. at 270°C. Therefrom it follows that the self-diffusion coefficient of lead ions equals 0.8·10−9 cm2/sec. In contrast, the self-diffusion coefficient of silver ions, derived from conductivity measurements of Koch and Wagner, amounts to 9.2·10−8 cm2/sec.
Isoconjugate Spectra and Variconjugate Sequences
Authors: Platt John R. 
Published: January 2005

Two molecules are isoconjugate or, more strictly, iso-π-electronic if they have the same number and geometrical arrangement of π-electrons bound about equally tightly in a planar conjugated system. Their π-electron spectra then show close resemblances. Example: aniline-styrene.
A variconjugate sequence is a series of such molecules in which the binding of some of the π-electrons and the appearance of the spectra slowly changes. Example: fluorobenzene (iso-π-electronic with benzene), phenol, aniline (iso-π-electronic with styrene). Here the heteroatoms are formally saturated and no transitions of nonbonding electrons (n-bands) are observed. Second example: phenyl cyanide (almost iso-π-electronic with benzene), benzaldehyde, phenyl azomethane (iso-π-electronic with styrene). Here the heteroatoms are formally conjugated and n-bands appear at long wavelengths in addition to the π-spectra. The location of the π-bands partly determines that of the n-bands.
The π-spectrum of every organic molecule with a closed-shell ground state lies on a variconjugate sequence between the π-spectra of two conjugated hydrocarbons. Several such sequences involving 90-odd compounds are displayed, showing the different binding of π- and n-electrons by different heteroatoms, and the interaction of n-bands of neighboring heteroatoms.
An examination is made of the general problem of assigning observed electronic transitions in organic-molecule spectra to particular theoretically predicted transitions. It is shown how variconjugate sequences could be useful in making such assignments.
The Phase Diagram of the BaO–TiO2 System
Authors: Statton W. O. 
Published: January 2005

A method for accurately observing phase changes at high temperatures has been developed; it employs a microfurnace and uses samples of oxide mixtures weighing less than 1 mg. The samples were observed and their temperatures measured with an optical pyrometer specially adapted for this purpose and calibrated for the furnace radiation. An electrically heated resistance strip, in general of molybdenum, allows melting and crystallization of the oxide mixtures at any desired speed. The samples were placed directly on the strip and could be quenched by interruption of the current flow.
The binary system, BaO–TiO2, was investigated. The existence of four compounds, BaTi4O9, BaTi2O5, BaTiO3, and Ba2TiO4, was demonstrated by liquidus curves and x-ray diffraction. A phase change of BaTiO3 below the solidus temperature was observed; all oxide mixtures with less than 80 mole percent TiO2 showed this intermediate BaTiO3 phase at about 1450°C.
Single crystals of BaTi4O9, BaTi2O5, and BaTiO3 were grown from ternary melts of BaCO3, TiO2, and BaCl2. The compound, BaTi4O9, showed extensive polymorphism. Attack by molten BaO mixtures on molybdenum and platinum produced the compounds, BaMoO4, Ba3Pt2O7, and Ba3Ti2PtO9.
The Cataphoresis of Spherical Fluid Droplets in Electrolytes
Authors: Booth F. 
Published: January 2005

A theory of the electrophoresis of spherical fluid droplets in an electrolyte is developed. A general formula is given for the electrophoretic velocity in terms of the applied field, the potential distribution in and near the drops, and the dielectric constants and coefficients of viscosity of the liquid and electrolyte. It is assumed that the liquid drop retains its spherical form in cataphoresis and also that relaxation effects in the electrolyte may be neglected.
Detailed formulas are worked out for the case of a Debye-Hückel potential in the electrolyte, and the following charge distributions in the fluid sphere.
(a) No charge within the sphere; the whole charge is concentrated on the interface.
(b) Uniform volume distribution of charge.
(c) Ionic double layer potential in the sphere.
It is shown that sundry special cases of the theory agree with previous computations and that it is not legitimate to apply theories of the cataphoresis of solid particles to fluid drops.
Elastic Relaxation and Structure of Liquids. I. Ultrasonic Absorption in Some Halogenated Methylenes, Ethanes, and Ethylenes
Authors: Sette Daniele 
Published: January 2005

In order to obtain information on the presence of structural effects in the elastic relaxation phenomena observed in liquids, the ultrasonic absorption was studied as a function of temperature in some organic compounds whose structure is correlated in a simple way. Large differences of absorption coefficient and of its temperature dependence have been found. It is difficult, at the present time, to understand clearly the results, but they show that the liquid structure has a great importance in the relaxation phenomena present in liquids.
Moreover an increase in dipole moment of the molecules is often present with an increase of absorption, showing that the dipole moment is not related in a simple way with the characteristics of relaxation phenomena and that all the interactions among the molecules are to be taken in account.
On the Elastic Relaxation in Carbon Disulfide: The Temperature Dependence of the Ultrasonic Absorption Coefficient
Authors: Sette Daniele 
Published: January 2005

The experimental values of the ultrasonic absorption coefficient given in the literature for carbon disulfide show the presence of dispersion in the frequency range 1–100 Mc/sec, but large differences are present in the values obtained by various authors at the same frequencies so that it is difficult to analyze the behavior of this liquid. In order to discriminate among the various results more information is needed. For this reason a measurement of the absorption coefficient was performed at 30 Mc/sec. The value obtained for α is in agreement with the higher values of the absorption coefficient obtained by other authors at various frequencies and, therefore, it gives more credence to them in comparison with others.
The absorption coefficient as a function of temperature does not follow a linear law as it does in other unassociated liquids. The temperature coefficient (1/α)(∂α/∂t) goes from 7.3·10−3 deg−1 at −23°C to almost zero near the boiling point. These results can be used to examine the theoretical explanations of absorption in carbon disulfide based on the assumption that all the vibrational modes relax together or on the hypothesis that they have different relaxation times. The value of the temperature coefficient at 25°C seems to be better explained with the first treatment.
I. Normal Frequencies of a One-Dimensional Crystal. II. An Approximation to the Lattice Frequency Distribution in Isotropic Solids
Authors: Halford J. O. 
Published: January 2005

I. The accurate expression for the individual frequencies of a linear crystal of any number of particles is derived.
II. It is shown that, for an isotropic three-dimensional array of uniform masses, the root-mean-square frequency is easily evaluated and the maximum square must always be less, but not much less, than twice the mean square. For two commonly studied simple cubic systems, the maximum square is evaluated and shown to be twice the mean square. The Debye expression for the frequencies in terms of standing wave components is modified empirically to give the correct maximum and mean squares by substituting linear crystal frequencies for the components and introducing a second force constant.
The resulting expression, a simplified form of the factored secular equation, should yield a more realistic and probably therefore a more widely useful distribution function than the Debye equation.
The Fluorescence of Acetone Vapor
Authors: Luckey G. W. , Noyes W. Albert 
Published: January 2005

An apparatus has been designed and built for the study of low fluorescence intensities. The ``blue'' fluorescence of acetone vapor has been investigated from pressures of about 1 mm to pressures of about 200 mm, at temperatures from 25°C to 300°C both with and without the addition of foreign gases, such as O2, NO, N2, and (CH3CO)2.
It is found at temperatures over about 100°C, and in the presence of O2 and NO, that there is no structure in the fluorescence of acetone which can be detected, and the wavelength of the intensity maximum is different from that found at 25°C. The shapes of the quenching curves are such as to demand at least two upper electronic states which participate directly or indirectly in the fluorescence phenomenon. This is in agreement with previous work. The photo-chemical data necessitate a high probability of predissociation of the initially formed state together with a small lifetime probably determined by the rate of predissociation. At least one other upper state, formed from the first through collisions, must be relatively insensitive to collisional deactivation. A complete theory cannot be given, but some important aspects are clear.
Spectroscopic Moment: A Parameter of Substituent Groups Determining Aromatic Ultraviolet Intensities
Authors: Platt John R. 
Published: January 2005

By the theory of Sklar and Förster, the added intensity produced in the benzene 2600A transition by monosubstitution is proportional to the square of a transition moment or ``spectroscopic moment'' induced by the substituent. The sign of the moment may be positive or negative. On disubstitution, para intensities are greater than meta and ortho if both signs are the same, less if they are opposite. The theory is used with available data to determine the relative spectroscopic moment for 25 different substituents. This moment is closely related to the ``mesomeric moment'' and to directing power, but the correlation is not perfect.
The theory is extended to account for intensity changes in the weak long-wavelength transitions (1A—1Lb) of derivatives of other cata-condensed ring systems, such as naphthalene, phenanthrene, 1,2-benzanthracene, etc. The increases of intensity produced by substituents, and their spectroscopic moments, appear to be almost identical with those found in benzene.
The Rotation-Vibration Spectrum of Methyl Cyanide in the Region 1.6μ—20μ
Authors: Venkateswarlu Putcha 
Published: January 2005

The infrared spectra of gaseous and liquid CH3CN have been investigated in the region 1.6μ—20μ with a Perkin-Elmer spectrometer using LiF, NaCl, and KBr prisms. The parallel type bands show, in general, a sharp Q branch and broad but more intense P and R branches. The perpendicular type bands are well resolved and show the expected intensity alternation ``strong, weak, weak, strong . . .'' of the subbands (Q branches).
All the fundamentals, except ν8(e), which is beyond the region investigated, have been definitely established and vibrational assignments have been made for all the observed bands.
Values for the rotational constants from microwave data have been used to obtain the Coriolis interaction constants,ζi, from the observed separations of the subbands of the ⊥ bands. The following values have been obtained: ζ5=0.10, ζ6=−0.44, and ζ7=0.41.
The Reactions of Methyl Radicals. IV. The Abstraction of Hydrogen Atoms from Cyclic Hydrocarbons, Butynes, Amines, Alcohols, Ethers, and Ammonia
Authors: Trotman-Dickenson A. F. , Steacie E. W. R. 
Published: January 2005

The photolysis of acetone in the presence of various compounds has been investigated between 70°C and 340°C. If the reaction CH3+CH3=C2H6has no activation energy, then the activation energies in kcal for the reactions of the type CH3+RH=CH4+Rare cyclopropane 10.3, cyclobutane 9.3, cyclopentane 8.5, cyclohexane 8.3, benzene 9.2, toluene 8.3, 1-butyne 9.1, 2-butyne 8.6, methanol 8.2, ethanol 8.7, iso-propanol 7.3, methyl ether 9.5, iso-propyl ether 7.3, monomethyl amine 8.4, dimethyl amine 7.2, trimethyl amine 8.8, and ammonia 10.0. The collision theory steric factors are of the order of 10−3 or less for all these reactions.
A table is presented summarizing the results so far obtained on methyl radical reactions by the photolysis of acetone in the presence of other compounds. The accuracy of the method and some of the general implications of the results are discussed.
Thermodynamic Investigations on Ternary Amalgams
Authors: Wagner Carl 
Published: January 2005

Under certain conditions, interaction between positively charged metal ions in an alloy may be considered to be of minor importance as compared to interaction between conduction electrons and metal ions. Then it follows that the activity of a solute metal 2 dissolved in metal 1 will be increased by a third component if metals 2 and 3 change the valence electron/atom ratio in the same direction. Conversely, the activity of a solute metal 2 will be decreased by a third component if metals 2 and 3 change the valence electron/atom ratio in opposite directions. Reference is made to the change in the solubility of hydrogen in copper by zinc, tin, aluminum, platinum, and nickel as alloying elements, to the change in the vapor pressure of zinc dissolved in copper by aluminum and nickel, and to the change in the activity of alkali metals dissolved in mercury by thallium.In addition, an equation is derived with the aid of which one may calculate the change in the activity of metal 2 dissolved in metal 1 due to the addition of a solute metal 3 if the changes in the activity coefficients with composition for the binary systems 1–2 and 1–3 are known and interaction between positively charged metal ions can be disregarded. This relation has been confirmed for the systems Hg–Li–Tl, Hg–Na–Tl, Hg–K–Tl, and Hg–Na–K.
Fractionation of the Carbon Isotopes in Decarboxylation Reactions. IV. The Relative Rates of Decomposition of 1-C12 and 1-C13 Trichloracetate Ions
Authors: Bigeleisen Jacob , Allen Thomas L. 
Published: January 2005

A precise determination of the relative rates of decomposition of 1-C12 and 1-C13 trichloracetate ions has been made. The 1-C12 ion has been found to decompose 1.0338±0.0007 times as fast as the 1-C13 ion into chloroform and bicarbonate at 70.4°C.
Trichloracetate ion has been found to undergo a decomposition reaction which gives chloride ion but no CO2, OH−, nor H+. The ratio of the rate constants for the production of Cl− and bicarbonate is 0.078.
The errors in the determination of the effect of isotopic substitution on the rates of chemical reactions are discussed. In the study of the isotopes of carbon, experiments using mass spectrometric analyses of C13 at the natural abundance level are capable of a precision of one order of magnitude better than ones in which the specific activity of C14 is determined by counting.
The Solution of Some Potential Problems in the Theory of Electrolytes
Authors: Booth F. 
Published: January 2005

The Poisson-Boltzmann equation for the potential in an electrolyte is solved for the following cases:
(a) Electrolyte bordered by a uniformly charged plane; (b) two semi-infinite electrolytes of different composition separated by a plane boundary; (c) electrolyte confined between parallel charged planes; (d) uniformly charged cylinder immersed in an electrolyte; (e) electrolyte in a cylinder with charged walls; (f) electrolyte between two concentric charged cylinders; (g) solid charged sphere in an electrolyte; and (h) sphere of electrolyte immersed in another electrolyte extending to infinity, and of different composition.
All the problems discussed are of interest in the theory of colloids or emulsions. In each case a series solution in powers of a parameter involving the charge or charges on relevant surfaces is given. The first term of each series is the solution of the Poisson-Boltzmann equation when the so-called Debye-Hückel approximation is applied to the equation. The additional terms are built up from the first by an iterative method. No restrictions on the compositions of the electrolytes are required.
Thermodynamics and Chemical Kinetics of One-Dimensional Nonviscous Flow through a Laval Nozzle
Authors: Penner S. S. 
Published: January 2005

Explicit relations have been obtained for the enthalpy changes in one-dimensional nonviscous flow through a Laval nozzle, where arbitrary deviations from thermodynamic equilibrium of chemical composition and of internal electronic, vibrational, or rotational energy states may occur. These relations are of interest in connection with calculations on the effect of deviations from equilibrium on performance of jet engines.
Starting with the equation of continuity for a multicomponent mixture of reacting gases, criteria for near-equilibrium and for near-frozen flow with respect to chemical reactions are derived. The near-equilibrium criteria agree with results obtained previously. The near-frozen flow criteria are new and have not yet been applied to the study of chemical reactions during nozzle flow.
Overlap and Bonding Power of 2s,2p-Hybrid Orbitals
Authors: Mulliken Robert S. 
Published: January 2005

A classification and nomenclature for 2s−2p hybrid AO's (atomic orbitals) of any degree of hybridization is proposed, and the concepts of cohybrids, antihybrids, and orthohybrids are defined. Overlap integrals S as follows are computed and tabulated as a function of the hybridization coefficient and the interatomic-distance parameter for the case of two like first-row atoms: S(hβ, hβ; ρ), S(hβ, hoβ; ρ), and S(1s, hβ; ρ). (See also Figs. 1 and 2.) Here hβ denotes any 2s−2p hybrid, and hoβ the corresponding orthohybrid. Slater AO's were used, and also, for selected ρ values for the case of C–C bonds, SCF AO's.
In connection with this work, and extending fragmentary tables given in a previous paper, complete tables from ρ=3 to ρ=14, for the case of two like atoms, are given for the overlap integrals S(1s, 2s), S(2s, 2s), S(1s, 2pσ), S(2s, 2pσ), S(2pσ, 2pσ), and S(2pπ, 2pπ) using orthogonalized Slater 2s AO's, and carbon SCF 2pσ and 2pπ AO's.
Tables of Slater-AO overlap integrals S(1s, hβ) are given as a function of β for the radicals FH, OH, NH, and CH at their equilibrium distances, also similar tables based on SCF AO's for the case of C–H bonds of lengths 1.12, 1.09, and 1.06A. (See also Fig. 3.)
The various tables and figures show that ``a little hybridization goes a long way''; that is to say, a small amount of s character in a pσ AO, or of pσ character in an s AO, causes a large change in S. Applications of this fact to problems of chemical binding are briefly suggested. These will be developed in a following paper. (Also see Note added in proof at end of this paper.)