Volume 11, Issue 2, April 1982
Index of content:
Microwave Spectra of Molecules of Astrophysical Interest. XXI. Ethanol (C2H5OH) and Propionitrile (C2H5CN)11(1982); http://dx.doi.org/10.1063/1.555662View Description Hide Description
The microwave spectra of ethanol (C2H5OH) and propionitrile (ethyl cyanide, C2H5CN) are critically reviewed and supplemented with spectral frequency calculations which include rotational and centrifugal distortion terms in the molecular Hamiltonian. The primary objective of this review is to provide the microwave transition frequencies applicable to molecular radio astronomy for the ground vibrational state of the most abundant isotopic forms, namely, 12C2H5 16OH and 12C2H5 12C14N. Since the internal rotation and hyperfine splittings for these species have not been resolved in most of the reported laboratory studies and also not detected in the molecular clouds observed by radio astronomers, these splittings have been ignored in the present calculations. All measured rotational transitions are included, however, the predicted transition frequencies were limited to J = 25 for ethanol and J = 30 for propionitrile over the range of 1 GHz to 300 GHz. A complete summary of the laboratory studies of both species is included for all isotopic forms with references to all prior studies.
11(1982); http://dx.doi.org/10.1063/1.555663View Description Hide Description
The heat capacity of polystyrene from 0 K to 600 K is reviewed on the basis of measurements on 29 samples reported in the literature. A set of recommended data for amorphous polystyrene is derived. The effect of tacticity on the heat capacity is also evaluated. Entropy and enthalpy functions are calculated. This paper is the fifth in a series of publications which will ultimately cover all heat capacity measurements on linear macromolecules.
Evaluated Kinetic and Photochemical Data for Atmospheric Chemistry: Supplement I CODATA Task Group on Chemical Kinetics11(1982); http://dx.doi.org/10.1063/1.555664View Description Hide Description
This paper updates and extends a previous critical evaluation of the kinetics and photochemistry of gas phase chemical reactions of neutral species involved in middle atmosphere chemistry (10–55 km altitude) [J. Phys. Chem. Ref. Data 9, 295 (1980)]. The work has been carried out by the authors under the auspices of the CODATA Task Group on Chemical Kinetics. Data sheets have been prepared for 228 thermal and photochemical reactions, containing summaries of the available experimental data with notes giving details of the experimental procedures. For each reaction a preferred value of the rate coefficient at 298 K is given together with a temperature dependence where possible. The selection of the preferred value is discussed, and estimates of the accuracies of the rate coefficients and temperature coefficients have been made for each reaction. The data sheets are intended to provide the basic physical chemical data needed as input for calculations which model atmospheric chemistry. A table summarizing the preferred rate data is provided, together with an appendix listing the available data on enthalpies of formation of the reactant and product species.