Transition-metal binding sites and ligand parameters

Abstract

A scale of ligand constants, P_L, is defined according to equation (1). This scale is used to analyse the E_½^ox of P_L=E_½^ox[Cr(CO)₅L]–E_½^ox[Cr(CO)₆](1) various closed-shell octahedral complexes [M₃L], in terms of the linear approximation of equation (2), where E_s is a E_½^ox[M_sL]=E_s+β. P_L(2) measure of the electron-richness of the site M_s and β a measure of its polarisability. Other properties of [M_sL] such as the type of ligand which binds to M_s, spectroscopic properties, and chemical reactivity are discussed in terms of the parameters P_L, E_s, and β. It is shown that equation (2) can be used in the identification of unknown [M_sL] and conversely in the design of electron-rich or -poor [M_sL].