Chemical Engineering Division (Argonne National Laboratory) Physical Inorganic Chemistry. Annual Report, July 1975--June 1976

摘要

The thermal conductivity of acetonitrile vapor has been measured at temperatures between 338 and 387 exp 0 K and pressures between 100 and 1050 torr. The pressure dependence of the thermal conductivities indicates the presence of dimeric vapor species with an association constant given by RT ln K sub 2 (atm exp -1 ) = 5002 - 21.15 T. Molecular orbital studies of hydrogen-bonded methyl alcohol vapor complexes indicate that, the cyclic tetramer is especially stable. Preliminary calculations on trifluoroethanol indicate that its dimer is more stable than that of methanol. Molecular dynamics calculations have been utilized to calculate the second-order coefficient of conformal ionic solution (CIS) theory. The results indicate that the repulsive part of the pair potential most commonly used for calculations on molten salts is inaccurate and that calculation of the CIS coefficient provides a sensitive test of pair potentials. Laser-Raman spectra of molten solutions of YCl sub 3 in CsCl, KCl and LiCl were obtained and compared with spectra of solids of known structure. The spectra at low concentrations of YCl sub 3 (X/sub YCl sub 3 / is less than 0.25) indicate an octahedrally coordinated YCl sub 63- species. Raman and infrared spectra of claudetite and arsenolite were measured and compared with the spectra of vitreous and liquid As sub 2 O sub 3 , as well as with the As sub 4 O sub 6 vapor molecules.The spectrum of claudetite has some resemblance to that of vitreous and liquid As sub 2 O sub 3 . Raman spectra of arsenous oxide indicate that the dimeric As sub 2 O sub 3 species is present. The Raman spectra of aluminum chloride vapor (AlCl sub 3 and Al sub 2 Cl sub 6 vapor molecules), provided nine new bands not observed before and permitted a more complete assignment and analysis of the structure of the species to be made. The Raman spectra of In(I), In(II) and In(III) chlorides indicate the presence of InCl, In(I)In(III)Cl sub 4 (In sub 2 Cl sub 4 ), InCl sub 3 , and In sub 2 Cl sub 6 species in the vapors. (ERA citation 03:007120)