Chemical Bonding in Monosubstituted Aromatic Molecules from Full-Valence Modern Ab Initio Valence Bond Calculations.

ABSTRACT: Modern ab initio valence bond theory is used to understand the bonding and electronic structure of nine monosubstituted aromatic molecules: fluorobenzene, aniline, toluene, phenol, benzonitrile, benzaldehyde, styrene, nitrobenzene, and benzoic acid. All sigma bonds and in-plane valence lone pairs are treated at the Generalized-Valence-Bond-Perfect-Pairing level while all the pi electrons are described at the Spin-Coupled level including up to all possible spin couplings. Through progressive restrictions on the spin function space, it is shown that in all the molecules considered there is no "pi bonding" between the substituents and benzene ring pi electrons. There are, however, quasi-classical electronic effects that indeed influence the aromatic electron sextet and the sigma bonds in diff

SUBMITTER: Barbosa AGH 

PROVIDER: S-EPMC12670402 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature