Variable‐Valent Rhenium Chemistry of Conjugated Nitrogenous Ligands: Structure and Reactivity

Abstract

AbstractThe valence states of particular concern in this review are VI–I and the ligand types are diimine, azoimine, imineamide and azooximeall bidentate and N,N‐coordinating. Metal reduction potentials and stability of oxidation states are subject to control via variation of the nature and extent of N,N‐chelation and coligation. Back‐bonding plays a major role in determining stability and isomer specificity, particularly in the valence domain III–I. Three types of mediated oxygen atom transfer processes have been scrutinized and modeled: from ReVO to tertiary phosphanes and variable‐spacer diphosphanes, from water to diimine and from oxime to metal/coligand. Other reactivity topics include isomerizations associated with ligand substitution, stable azo anion radical generation and azo cleavage. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)