Analysis of Different Computational Treatments of Highly Strained Molecules.

摘要

As part of an extended study of the highly strained systems tetrahedrane (I), its aza analogues (II-V) and their nitro derivatives, we have used the GAUSSIAN 86 system of programs to calculate the structures, vibrational frequencies and bond orders of I-V at several different computational levels, ranging from minimum basis Self Consistent Field (STO-3G) to second order Moller-Plesset perturbation theory (MP2/6-31G*). The structures, vibration frequencies and bond orders of tetrahedrane and its aza analogues have been calculated and compared at several different computational levels, two of which include correlation contributions. The STO 3G basis is found to produce remarkably good geometries. For each type of bond, the same trend in bond orders is obtained at each computational level. Keywords: Organic nitrogen compounds, Reprints. (AW)