Structural and electronic origin of the conformational behavior of biphenyl-like α-diimine ligands. A theoretical study

Abstract

The conformational behavior of aromatic α-diimines has been analyzed by means of ab initio computations making use of the standard STO-3G minimal basis set. The absolute minimum of the potential energy curve always corresponds to the planar trans conformation and a secondary minimum is also found for a non planar cisoid conformation. An alternate analysis, rooted in bond energy calculations explicitly involving the charges of the bond-forming atoms, indicates that bonded rather than nonbonded interactions are responsible for the observed conformational preferences.