Butadiene and benzene π‐electron SCF ground states in the bond orbital resonance theory approach

Abstract

AbstractButadiene and benzene SCF ground states are analyzed using the bond orbital resonance theory (BORT) approach. The results obtained are compared with the analogous description of these states within the VB approach. It is shown that the structural weights of BORT Kekulé structures are much larger than the structural weights of the corresponding VB Kekulé structures. For example, in the butadiene case the structural weight of the BORT Kekulé structure is over 0.941, while the structural weight of the VB Kekulé structure is only 0.221. In addition, in the BORT approach one has to consider a much smaller number of resonance structures than in the VB approach. This suggests that the description of conjugated systems should be more successful in the BORT than in the VB basis, and that formal Kekulé structures should be interpreted in the BORT and not in the VB sense.