Abstract: | The geometrical parameters, normal vibration frequencies, and thermochemical characteristics of the Na2Cl+, NaCl 2 − , Na3Cl 2 + , and Na2Cl 3 − ions in saturated vapors over sodium chloride were calculated by the ab initio methods including electron correlation. According to calculations, the Na2Cl+ and NaCl 2 − triatomic ions have a linear equilibrium D ∞h configuration. The pentaatomic ions can exist in the form of the D ∞h linear isomer, C 2v planar cyclic isomer, or D 3h bipyramidal isomer. At ∼1000 K the Na3Cl 2 + and Na2Cl 3 − ions exist predominantly in the form of the linear isomers. The energies and enthalpies of the ion-molecule reactions involving the above ions were calculated. The formation enthalpy of the ions Δf H 0(0 K) was determined: 230 ± 2 kJ/mol (Na2Cl+), −96 ± 4 kJ/mol (Na2Cl 3 − ), −616 ± 2 kJ/mol (NaCl 2 − ), and −935 ± 4 kJ/mol (Na2Cl 3 − ). Original Russian Text Copyright ? 2007 by T. P. Pogrebnaya, A. M. Pogrebnoi, and L. S. Kudin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No. 6, pp. 1053–1061, November–December, 2007. |