AB Initio and Semi-Empirical Calculations on the Oxyhalides of Silicon.

摘要

In 1982 the heats of formation of the silicon oxyhalides were determined by experiment to be -267.9 Kcal/mole (SiOF2), -167.8 (SiOC2), -137.4 (SiOBr2), and -99.4 (SiOI2). MNDO-PM3 semiempirical calculations indicate that the heats of formation are nearer to -229.4, -121.2, -94.1, and -50.2 Kcal/mole respectively. Ab-initio calculations using a 6-31G(d) basis set confirm the semiempirical results for the fluoride and chloride systems. Keywords: Thermochemical data; Silicon oxyhalides; Reprints. (js)