Influence of methyl functional groups on the stability of cubane carbon cage
Abstract We present a quantum chemical study to elucidate the structure, energetics and stability of isolated polymethylcubane molecules C 8 H 8 q (CH 3 q The results obtained by means of originally developed nonorthogonal tight binding approach are in good agreement with the existed experimental data for solid octamethylcubane C 8 (CH 3 8 The isomerization mechanisms for polymethylcubane family are studied in detail and the minimum energy barriers' heights preventing the decomposition are calculated. The temperature dependence of octamethylcubane molecule lifetime to the decomposition moment was determined by direct molecular dynamics simulation. It is shown that methyl groups destabilize the cubic carbon cage, but less than nitro groups.