Synthesis and structure of novel rhodium complexes of multi-functionalised amine-phosphine ligands

Abstract

The coordination behaviour of a variety of amine containing phosphine ligands has been studied. Two new multifunctionalised ligands have been prepared and shown along with three known ligands to favour a variety of coordination modes when complexed with rhodium(III) centres. The hemilabile P^∧N chelate ligands show three different types of behaviour: strong P,N chelation even in the presence of chloride ions, strong P,N chelation after a chloride ligand is removed (Ag salts), and weak coordination after chloride abstraction. Five of the complexes have been characterised by X-ray crystallography. Multinuclear NMR and IR spectroscopies were also highly diagnostic in assigning the coordination chemistry favoured by each ligand.