Geometry predictions for π-bonded molecules using simplified MO theory

Abstract

A simplified version of Walsh's diagrams is proposed. Using this MO-based scheme, the angular geometry at dicoordinate and tricoordinate atoms in covalent molecules can be predicted, even when π bonding exists in the system. The basic “rule of thumb” developed in that distortion from the geometry of highest symmetry will occur only if the in-plane p orbital at the center of interest contains some antibonding, or appreciable nonbonding, electron density. These predictions are tested for a wide variety of molecules.