Showing papers in "Journal of Physical and Chemical Reference Data in 2007"
TL;DR: In this paper, an interpolation function that precisely represents e(ν,t) at standard atmospheric pressure was derived for frequencies and temperatures in the ranges 0⩽ν⩻25THz and 0 ⩽t⩾100°C.
Abstract: All the currently available experimental permittivity data for pure water are used to derive an interpolation function that precisely represents e(ν,t,) at standard atmospheric pressure, for frequencies and temperatures in the ranges 0⩽ν⩽25THz and 0⩽t⩽100°C. The permittivity data is represented in terms of relaxations and resonances processes. There are three relaxations in the microwave region and two resonances in the far infrared. The temperature dependence of the relaxation and resonance parameters are determined. For example, at 25°C the three relaxation frequencies are 18.56GHz, 167.83GHz, 1.944THz and the two resonance frequencies are 4.03 and 14.48THz.
557 citations
TL;DR: In this paper, the vibrational zero-point energies (ZPEs) of 85 diatomic molecules were derived from published spectroscopic constants and standard uncertainties, including estimated contributions from bias as well as the statistical uncertainties propagated from those reported in the spectroscopy literature.
Abstract: Vibrational zero-point energies (ZPEs), as determined from published spectroscopic constants, are derived for 85 diatomic molecules. Standard uncertainties are also provided, including estimated contributions from bias as well as the statistical uncertainties propagated from those reported in the spectroscopy literature. This compilation will be helpful for validating theoretical procedures for predicting ZPEs, which is a necessary step in the ab initio prediction of molecular energetics.
352 citations
TL;DR: In this article, the energy levels and observed spectral lines of the krypton atom, in all stages of ionization for which experimental data are available, have been compiled, and sufficient data were found to generate level and line tables for Kr I-Kr X and Kr�XVIII−Kr�XXXVI.
Abstract: The energy levels and observed spectral lines of the krypton atom, in all stages of ionization for which experimental data are available, have been compiled. Sufficient data were found to generate level and line tables for Kr I–Kr X and Kr XVIII–Kr XXXVI. For Kr XXXV and Kr XXXVI and most of Kr XXXIV theoretical values are compiled for the energy levels. In all of the other stages a few lines, some of which may be only tentative classifications, are reported. In addition for Kr I, separate tables of energy levels are tabulated for the isotopes 86Kr and 84Kr. Experimental g factors are included for Kr I and Kr II. A value, either experimental, semiempirical, or theoretical, is included for the ionization energy of each ion.
104 citations
TL;DR: In this paper, the energy levels and spectral lines of gallium atom in all stages of ionization have been compiled for spectra Ga I through Ga VII, Ga XIII through Ga XXVI, and Ga XXX.
Abstract: The energy levels and spectral lines of gallium atom in all stages of ionization have been compiled. Experimental data on spectral lines and energy levels exist for spectra Ga I through Ga VII, Ga XIII through Ga XXVI, and Ga XXX. For Li-like Ga XXIX through H-like Ga XXXI, theoretical data on energy levels and line wavelengths are compiled. For Ga I, Ga II, and Ga III we include radiative probabilities of electric-dipole transitions where available. For Ga XV through Ga XX, Ga XXIII through Ga XXVI, and Ga XXX, radiative probabilities of magnetic-dipole and electric-quadrupole transitions are included. The ground state configuration and term and a value of ionization energy are included for each ion.
65 citations
TL;DR: In this article, the transition probabilities for important lines of neutral and singly ionized carbon and nitrogen were assessed and tabulated for a large number of forbidden lines (M1, M2, and E2 lines).
Abstract: We have undertaken new critical assessments and tabulations of the transition probabilities for important lines of neutral and singly ionized carbon and nitrogen. Our updates primarily address the persistent lower transitions as well as a greatly expanded number of forbidden lines (M1, M2, and E2 lines). For these transitions, sophisticated multiconfiguration Hartree–Fock calculations have been recently carried out, which have yielded data considerably improved and often appreciably different from our 1996 NIST compilation.
64 citations
TL;DR: The latest evaluation of atomic weight determinations and other cognate data has warranted 16 changes for the standard atomic weights of the elements, Ar(E), from those published previously in the Table of Atomic Weights 2001.
Abstract: The latest evaluation of atomic weight determinations and other cognate data has warranted 16 changes for the standard atomic weights of the elements, Ar(E), from those published previously in the Table of Atomic Weights 2001. The revised standard atomic weight are as follows: Ar(Al)=26.9815386(8), Ar(Bi)=208.98040(1), Ar(Cs)=132.9054519(2), Ar(Co)=58.933195(5), Ar(Au)=196.966569(4), Ar(La)=138.90547(7), Ar(Mn)=54.938045(5), Ar(Nd)=144.242(3), Ar(P)=30.973762(2), Ar(Pt)=195.084(9), Ar(Sm)=150.36(2), Ar(Sc)=44.955912(6), Ar(Na)=22.98976928(2), Ar(Ta)=180.94788(2), Ar(Tb)=158.92535(2), Ar(Th)=232.03806(2). A recommendation is made that δ13C values of all carbon-bearing materials be measured and expressed relative to Vienna-Pee Dee Belemnite on a scale normalized by assigning consensus values of −46.6‰ to L-SVEC lithium carbonate and +1.95‰ to NBS 19 calcium carbonate.
53 citations
TL;DR: In this paper, a new group contribution method based on Benson's group additivity technique was developed to estimate as precisely as possible solid state enthalpies of formation, at 298.15 K, of Carbon-H compounds, C-H-N-O compounds, and Carbon-Hydrogen-Nitrogen-Oxygen compounds.
Abstract: A program has been undertaken to develop a new group contribution method, based on Benson's group additivity technique, estimate as precisely as possible solid state enthalpies of formation, at 298.15 K, of C-H compounds, C-H-O compounds, and C-H-N-O compounds. A set of 1017 experimental values of the enthalpy of formation has been studied and compared to the predicted values of this new method as well as the method of Domalski and Hearing. This new estimation technique leads to a higher precision and reliability. With the inclusion of additional group values, a wider range of compounds can be studied (compared to the Domalski and Hearing technique). Comparison with a quantum mechanical method [Rice et al., Combust. Flame 118, 445 (1999)] shows that the list of group contribution values, ring strain corrections, and non-nearest neighbor interactions provided here yields better estimates overall. Prediction of Enthalpy of Formation in the Solid State (at 298.15 K) Using Second-Order Group Contributions-Part 2: Carbon-Hydrogen, Carbon-Hydrogen-Oxygen, and Carbon-Hydrogen-Nitrogen-Oxygen Compounds.
53 citations
TL;DR: The mutual solubility and related liquid-liquid equilibria of C4 alcohols with water were exhaustively and critically reviewed in this paper, where all the systems sufficient data are available to allow critical evaluation.
Abstract: The mutual solubility and related liquid–liquid equilibria of C4 alcohols with water are exhaustively and critically reviewed. Reports of experimental determination of solubility in three chemically distinct binary systems that appeared in the primary literature prior to end of 2004 are compiled. For all the systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units. In addition to the standard evaluation criteria used throughout the Solubility Data Series, a new method based on the evaluation of all experimental data for a given homologous series of saturated alcohols was used.
45 citations
TL;DR: In this paper, a quantitative structure-property relationship (QSPR) strategy was used to fill significant lacks in the empirical data for 75 chloronaphthalenes (CNs) by using quantum-chemical descriptors computed on the level of density functional theory.
Abstract: n-octanol/water and n-octanol/air partition coefficients were calculated for 75 chloronaphthalenes (CNs) by means of quantitative structure-property relationship (QSPR) strategy to fill significant lacks in the empirical data. The QSPR models based on quantum-chemical descriptors computed on the level of density functional theory using B3LYP functional and 6-311++G** basis set. For each property, six models were identified using chemometric approaches such as: multiple regression method, principal component regression, partial least square regression, partial least square regression with initial elimination of the uninformative variables, partial least square regression with variable selection by a genetic algorithm (GA-PLS), and neural networks with variable selection by a genetic algorithm (GA-NN). They were calibrated and validated using the experimentally measured values of logKOW available for 16 congeners and the values of logKOA existing for 43 congeners. The models were compared regarding to their...
42 citations
TL;DR: In this paper, a review serves to update previously published evaluations of equilibrium constants and enthalpy changes for enzyme-catalyzed reactions and provides commentary on the data and on any corrections which have been applied to the data or any calculations for which the data have been used.
Abstract: This review serves to update previously published evaluations of equilibrium constants and enthalpy changes for enzyme-catalyzed reactions. For each reaction, the following information is given: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the conditions of measurement [temperature, pH, ionic strength, and the buffer(s) and cofactor(s) used], the data and their evaluation, and, sometimes, commentary on the data and on any corrections which have been applied to the data or any calculations for which the data have been used. The review contains data from 119 references which have been examined and evaluated. Chemical Abstract Service registry numbers are given for the substances involved in these various reactions. There is also a cross reference between the substances and the Enzyme Commission numbers of the enzymes used to catalyze the reactions in which the substances participate.
34 citations
TL;DR: In this article, the microwave spectrum of methylamine in its ground vibrational state is reviewed and supplemented with spectral frequency calculations derived from rotation-internal rotation-inversion analysis.
Abstract: The microwave spectrum of methylamine in its ground vibrational state is critically reviewed and supplemented with spectral frequency calculations derived from rotation-internal rotation-inversion analysis The review covers the frequency range from 1 to 500 GHz and includes the transitions with rotational quantum number J from 0 to 30 The calculated frequency with uncertainty at the 95% confidence limit along with the lower state energy and line strength are presented For J ⩽ 10 transitions and some J > 10 transitions exhibiting large hyperfine splittings, the quadrupole hyperfine structure is also tabulated
TL;DR: In this article, four analytical predictive correlations were used to compare the data for the vaporization enthalpy accepted in the Design Institute for Physical Property Data® (DIPPR®) database with those given by general correlations based on the corresponding-states method.
Abstract: Data for the vaporization enthalpy accepted in the Design Institute for Physical Property Data® (DIPPR®) database are compared with those given by general correlations based on the corresponding-states method. In particular, four analytical predictive correlations were used. Three of them require as input the critical temperature and the acentric factor. The fourth requires a molecular Lennard-Jones parameter and the acentric factor. Results obtained for 1576 fluids indicate that the recommended model for an overall use, in order to reproduce the DIPPR data, is the one proposed by Sivaraman et al. [Ind. Eng. Chem. Fundam. 23, 97 (1984)].
TL;DR: In this article, the effect of the sample history and heating process on the glass transition temperature of disaccharides in aqueous solutions was investigated. But the results were limited to the case of trehalose and water.
Abstract: Glass transition temperatures (Tg) for sucrose, trehalose, and water have been determined by numerous studies in the past. Literature values appear to be fairly scattered and compromise the applicability of the Gordon–Taylor equation for aqueous solutions. This work deals with the effect of the sample history and heating process on the Tg values. Consistent estimates for the glass transition temperature of both disaccharides in aqueous solution can be made from these observations.
TL;DR: Energy levels and hyperfine structure constants have been compiled for the sixteen longest lived isotopes of francium (Z=87) for most isotopes with atomic weights in the range 199 ≤A≤232 as mentioned in this paper.
Abstract: Energy levels and hyperfine structure constants have been compiled for the sixteen longest lived isotopes of francium (Z=87). For most isotopes with atomic weights in the range 199 ≤A≤232 the only measurements made are for the 7sS1∕22 and 7pP1∕2,3∕2°2 levels. Additional energy-level data are available for Fr210, Fr212, and Fr221. Wavelengths with classifications and transition probabilities are tabulated for Fr212. In addition, the ionization energy is included for isotopes for which a sufficient number of levels have been measured, Fr212 and Fr221.
TL;DR: In this paper, a multilayer feed-forward neural network was used for regression of thermodynamic properties of pure fluids. But the model was applied to sulfur hexafluoride aiming at drawing its dedicated equation of state in a heuristic mode from the available experimental data.
Abstract: An innovative method for the regression of thermodynamic properties of pure fluids was recently proposed. The technique, indicated as an extended equation of state, adopts a framework similar to the extended corresponding states method, but a cubic equation is assumed instead of the equation of state of the reference fluid and the shape functions are expressed through a multilayer feedforward neural network. The use of a neural network assures a very high flexibility of the functional form to be regressed, so the resulting model reaches a representation accuracy which is comparable to that attained by the state-of-the-art multiparameter equations of state in the representation of the thermodynamic properties of a pure fluid. The technique was applied here to sulfur hexafluoride aiming at drawing its dedicated equation of state in a heuristic mode directly from the available experimental data. For sulfur hexafluoride (critical point is at Tc=318.7232K and Pc=3.754983MPa), experimental data of several prope...
TL;DR: In this paper, the solubility of inorganic compounds of actinides except for carbonates and nitrates is presented. But the solusability data for actinium, protactinium and transamericium is not included in this volume.
Abstract: This volume presents the solubility of inorganic compounds of actinides except for carbonates, which are included in Volume 74 of this series, and nitrates, which are covered in Volume 55 Also included are solubility data of compounds such as organosulfates, phosphates, and arsenates, which are not covered in Volume 74 The predominant part of this volume covers solubility data of thorium, uranium, neptunium, and plutonium compounds Fewer data have been published for americium compounds and very few for compounds of actinium, protactinium, and transamericium elements The literature has been covered up to the end of 2004 Documents which remained unavailable to the editor, and could not be included in the volume are listed in the Appendix For some compounds it was not possible to show the Chemical Abstracts registry numbers since these have not been assigned
TL;DR: In this article, the recommended liquid-liquid equilibrium (LLE) data for 12 binary ether-water systems have been obtained after the critical evaluation of all data (168 data sets) reported for 17 systems in the open literature up to the end of 2006.
Abstract: Recommended liquid-liquid equilibrium (LLE) data for 12 binary ether-water systems have been obtained after the critical evaluation of all data (168 data sets) reported for 17 systems in the open literature up to the end of 2006. An equation for the prediction of the ether solubilities in water was developed. The predicted ether solubilities were used for the calculation of water solubility in the ether-rich phase. The LLE calculations were done with the equation of state appended with a chemical term (EoSC) proposed by Goral [Fluid Phase Equilib. 118, 27 (1996)]. The recommended data are presented in the form of individual tables with references. Using these recommended data, predictive ability has been tested for several UNIFAC and ASOG group-contribution methods.
TL;DR: The mutual solubility and liquid-liquid equilibria of acetonitrile ternary and quaternary systems with liquid solvents are reviewed in this paper.
Abstract: The mutual solubility and liquid-liquid equilibria of acetonitrile ternary and quaternary systems with liquid solvents are reviewed. The solvents include water, inorganic compounds, and a variety of organic compounds such as hydrocarbons, halogenated hydrocarbons, alcohols, acids, esters, and nitrogen compounds. A total of 191 ternary and 35 quaternary systems whose properties were described in the chemical literature through 2000 are compiled. For 37 systems sufficient data were available to allow critical evaluation. All data are expressed as mass % and mole fractions as well as the originally reported units. Similar reviews of gas, liquid, and solid solubilities for other systems were published earlier in the International Union of Pure and Applied Chemistry Solubility Data Series. This is Volume 83 of this series.
TL;DR: In this paper, the authors calculated the radiative and nonradiative lifetimes of the diatomic potassium hydride, KH, molecule using the Fermi's Golden Rule treatment in coupling calculation.
Abstract: In this article, dynamic couplings for X-A, X-C, and A-C, by using first and second derivatives terms neglected in the Born–Oppenheimer approximation, are calculated. Newly calculated radiative transition probabilities for the A1Σ+→X1Σ+ and C1Σ+→X1Σ+ emission bands of KH are used to calculate the radiative and nonradiative lifetimes of the various vibrational levels (0⩽v⩽35) and (0⩽v⩽55) of A1Σ+ and C1Σ+ states of the diatomic potassium hydride, KH, molecule. For higher vibrational levels, an estimate of the bound-to-free emission probability is also needed and included. Accurate positions, radiative and nonradiative lifetimes of states belonging to the adiabatic A and C states of the KH molecule are estimated. The results come from a Fermi’s Golden Rule treatment in coupling calculation. That confirms the accuracy reached in both approaches and also in the treatment of the diabatic-adiabatic transformation. It involves, in particular, an effective phase choice that is needed to properly estimate nonadiab...
TL;DR: The reference numbers in this column for the first spectral line of Multiplet No. 1 should read “15, 18, 31.” The reference numbers for the remaining spectral lines second through fifth within this multiplet No., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18 n, 31 n, 18 n, 31 n.
Abstract: All of the reference numbers in the last column Source of Table 8 C II: Allowed Transitions on pages 1307–1309 are incorrect. The reference numbers in this column for the first spectral line of Multiplet No. 1 should read “15, 18, 31.” The reference numbers for the remaining spectral lines second through fifth within this multiplet No. 1 should read “18 n , 31 n .” All of the reference numbers in the remaining multiplets Nos. 2–25 should read “31.”
TL;DR: In this paper, the properties of the seven target bicyclic epoxides are calculated using the density functional methods, and enthalpies of formation are determined at B3LYP∕6-31G(d,p) calculation level using isodesmic and homodesmic working reactions with the ΔrxnH° and known enthalpies.
Abstract: Thermochemical properties, ΔfH°(298), S°(298) and [Cp°(T)] (10K⩽T⩽5000) of the seven target bicyclic epoxides are calculated using the density functional methods. Molecular structures and vibration frequencies for 6-oxabicyclo[3.1.0]hexane, 7-oxabicyclo[4.1.0]heptane, 8-oxabicyclo[5.1.0]octane, 7-oxabicyclo[2.2.1]heptane, endo-2-methyl-7-oxabicyclo[2.2.1]heptane, exo-2-methyl-7-oxabicyclo[2.2.1]heptane and 7-oxabicyclo[4.1.0]hept-2,4-ene are calculated at the B3LYP∕6-31G(d,p) level of theory. Enthalpies of formation are determined at B3LYP∕6-31G(d,p) calculation level using isodesmic and homodesmic working reactions with the ΔrxnH° and known enthalpies of reference species in each of three different work reactions. Entropy (298) and heat capacity [Cp°(T)] values along with Benson Group additivity parameters are reported for each ring system. Data previously reported on oxybicyclo-epoxides are summarized.