Electron‐Pair Repulsions and Molecular Shape

Abstract The theory described in this article emphasizes the importance of interactions between the electron pairs in the valence shell of a central atom in determining stereochemistry and it assumes that interactions between the ligands are generally of lesser importance although sufficiently bulky groups, or chelate ligands, may play an important role in determining the stereochemistry. If lone‐pair electrons are present in the valence shell of the central atom then the two theories (the theory of interaction of electron pairs and the theory of interaction between ligands) predict different structures. In the great majority of cases the determined structures are those expected if it is assumed that lone pairs are stereochemically active, i.e. if repulsions between electron pairs in the valence shell determine stereochemistry.