On the geometric structure and vibrational frequencies of o-benzyne. An ab initio study including electron correlation

Abstract

The geometry of o-benzyne has been fully optimized using a single-pair GVB wavefunction and a 3-21G and 6-31G* basis. The geometry obtained differed significantly from that found in the absence of electron correlation, and has cumulene-like features. A consistent assignment of the experimental vibrational spectrum is made using vibrational frequencies calculated at this predicted geometry.