Computational study of relative bond strengths and stabilities of a series of amine and nitro derivatives of triprismane and some azatriprismanes

Abstract

An ab initio SCF-MO procedure has been used to compute the structures, bond orders, and isodesmic reaction energies of various NH2 and NO2 derivatives of triprismane and some azatriprismanes. Each of these substituents, individually, is found to have a weakening influence upon one or more bonds. The presence of aza nitrogens in the molecular framework enhances this tendency for the NH2 group but essentially eliminates it for NO2. No reinforcement (‘push-pull” effect) is observed when the two substituents are present simultaneously on adjacent carbons. The NH2 group is found to diminish the strain energies of these molecules; however the effect of the NO2 appears to depend upon the number of aza nitrogens.