Electrochemical studies of transition metal complexes

• Main Author: Usher, Peter I.
• Published: University of Edinburgh 1995
• Subjects: 541.37
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.663161

This thesis is concerned with the spectroscopic, electrochemical and spectroelectrochemical investigation of a range of transition metal species, all containing the ligand 2,2'-bipyridine (bpy). All the complexes studied exhibit rich electrochemistry and electronic absorption spectra. Chapter one details the electrochemical and spectroelectrochemical techniques used in this work, and presents a brief overview of the reasons why we study transition metal complexes in this manner. Chapter two is concerned with the solvent dependent behaviour of complexes of the form [M(bpy)<SUB>2</SUB>(CN)<SUB>2</SUB>] (M = Fe, Ru or Os). The electrochemistry, UV/visible spectroscopy and spectroelectrochemistry of these complexes in a range of solvents is described, and both reduced and oxidised forms of the complex are investigated. The solvent dependent characteristics of the complexes are compared with a range of solvent parameters, and show best agreement with Acceptor Numbers. Analysis of epr data for the oxidised complexes, and spectroelectrochemical experiments suggest that the solvent interaction responsible for this behaviour is minimised on removal of an electron. Chapter three details a range of mono- and bi-metallic complexes containing Ru(bpy)<SUB>2</SUB> or Fe(bpy)<SUB>2</SUB> units and poly-aromatic bridging ligands. The electrochemistry UV/visible spectroscopy and spectroelectrochemistry of these complexes is described. Chapter four details the attempted synthesis of three complexes utilising cyanide ligands as a bridge between two metal centres. These complexes are based around either a [Ru(bpy)<SUB>2</SUB>(CN)<SUB>2</SUB>] or [Pt(bpy)(CN)<SUB>2</SUB>] centre. The electrochemistry UV/visible spectroscopy and spectroelectrochemistry of the products is reported, and the likely nature of the products is discussed.