Stereochemistry of five-co-ordination. Part IV. Compounds of stoicheiometry (bidentate ligand)tris(unidentate ligand)metal

Abstract

Repulsion-energy calculations show that for compounds of the type [M (bidentate)(unidentate)₃]^x± a long trough exists on the potential-energy surface which includes a distorted square pyramid, with the bidentate ligand spanning one of the square edges, and a trigonal bipyramid with the bidentate ligand spanning one of the non-equatorial edges. Intramolecular rearrangements along this trough can be considered as free rotation of the bidentate ligand about the metal–bidentate ligand axis, above the triangular arrangement of the three unidentate ligands. The effects of varying the bidentate ligand bite, and the metal–ligand bond lengths, are discussed.