A Theoretical Study of Conjugation in Para-Substituted Nitrobenzenes
Abstract
The much-debated electronic structure of para-substituted nitrobenzene us studied by means of fully optimized geometric analysis of variously substituted nitrobenzenes in which the electronic character of the investigation concerns the electronic effects of Hammett sigma values. The investigation concerns the electronic effects of substituent to ring conjugation on six parameters: barrier to rotation of the NO2 group, C-N bond length, ring C-C bond lengths and substituent to ring bond lengths, p(z) orbital overlap between the NO2 group and the ring, and the charge density on the NO2 oxygens. It is theorized that the change in barrier to rotation over the sigma spectrum is directly related to the degree of conjugation to the nitro group. The data, gathered from AM1 calculations on the semi-empirical level, show that the hybrid valence bond structure of p-nitrobenzene does receive a significant contribution from an electronic configuration which is stabilized by through-resonance. (js)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 22, 1990
- Accession Number
- ADA227167
Entities
People
- James R. Barney
Organizations
- United States Naval Academy