Stereochemistry of five-co-ordinate compounds ML3X2: crystal and molecular structure of dichlorotris(5-ethyl-5H-dibenzophosphole)nickel(II)

Abstract

The nickel atom in the title compound is five-co-ordinate. It has a trigonal bipyramidal disposition of its bonds with two chlorine atoms in equatorial positions. This isomeric form is different from the three previously found in eight closely related compounds.

Variation of isomeric form among the compounds ML₃X₂ is related to possible overcrowding of the five immediate atomic neighbours of the metal atom and to other factors. Details concerning particular valency angles in the series are explained by steric effects and an interaction between two of the three aromatic ligands.