Some transition metal chemistry relevant to organometallic chemistry

Abstract

The character of bonds between transition metal centres and attached groups or ligands can span the whole range from electrostatic to covalent. This is reflected in the approximations which have been used to discuss the coordinate bond. On the one hand crystal field theory starts from the assumption that the interactions between transition metal ions and ligands are entirely electrostatic. While this approach is useful in explaining magnetic and spectroscopic properties of aquo and ammine complexes, for example, especially when allowance is made for some covalency, it is far from successful in treating the essentially covalent compounds formed by ligands such as carbon monoxide, unsaturated hydrocarbons or alkyl and aryl phosphines.