Calculation of retention indexes of alkyloxazoles and alkylthiazoles in capillary chromatography

The retention indexes of 41 alkyloxazoles and alkylthiazoles have been determined at 110°C on capillary columns with OV-101/KF, Triton X-305/KF, and PEG-40M/KF, and the contributions calculated to the retention indexes of the methyl, ethyl, and propyl groups at different positions in the rings. The magnitude of the contribution for each alkyl group depends on its position in the ring; this has been used in the calculation schemes to predict the retention indexes of di- and trisubstituted oxazoles and thiazoles with different alkyl radicals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1338–1344, June, 1990.     

Accuracy in the determination of thermodynamic solution functions from retention indexes

Conclusions Equations are proposed for evaluating the accuracy in the determination of the relative distribution coefficients, separation factors, differences in partial molar enthalpies, entropies, and free energies of solution from retention indexes which give an error of the same order of magnitude as the gas-chromatographic method of determination from specific retention volumes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 632–635, March, 1972.     

Thermodynamic evaluation of the interaction of fatty acid methyl esters with polar and non-polar stationary phases,based on their retention indices

Summary Kovát retention indices are used to determine the partial molar free energies of solution of 39 methyl esters of saturated (normal and branched), mono- and poly-unsaturated higher fatty acids in the non-polar phase Se-30 and the polar phase SILAR 5CP. Contributions of double bonds as a function of their number and position in the acid chain to the partial molar free energies of solution (G) are evaluated quantitatively. Linear equations are suggested for the calculation of G of any compounds from their retention indices measured in columns with SE-30 and SILAR 5CP.     

Coupling of the lattice and superlattice deformations and hysteresis in thermal expansion for the quasi-one-dimensional conductor TaS3

An original interferometer-based setup for measurements of length of needlelike samples is developed, and thermal expansion of o-TaS(3) crystals is studied. Below the Peierls transition the temperature hysteresis of length L is observed, the width of the hysteresis loop deltaL/L being up to 5 x 10(-5). The behavior of the loop is anomalous: the length changes so that it is in front of its equilibrium value. The hysteresis loop couples with that of conductivity. With lowering the temperature down to 100 K the charge-density waves' elastic modulus grows achieving a value comparable with the lattice Young modulus. Our results could be helpful in consideration of different systems with intrinsic superstructures.