DENSITY-FUNCTIONAL CALCULATIONS ON JAHN-TELLER EFFECT OF TETRACHLOROMETHANE CATION

Density functional (DF) calculations of the tetrachloromethane cation and its most important competitive process, the formation of CCl3+, we re carried out to explain the possible stability of CCl4+. From result s obtained with B-LYP and B-P86 methods, it is possible to produce a s light Jahn-Teller (JT) effect for a C-s planar structure of the cation type CCl2-Cl-Cl+ compatible with the experimental data obtained by el ectron-spin resonance spectroscopy. A complex of C-3v structure CCl3+- Cl which is similar to the previous one found in CF4+ appears when sym metry-broken wave functions are used in HF-LYP and HF-P86 methods. Dep ending of the DF method employed, either on e of the minima [C-s (plan ar) and C-3v] is the most stable and competes with the dissociation of the molecular ion to give CCl3+. The JT stabilization energy is small er when the JT active coordinates are considered.