Aspects of Carbonyl Cluster Chemistry

Abstract

Research in cluster chemistry has been driven not only by the intrinsic interest in these closed polyhedral molecules, but also by their relevance to catalysis, surface science, chemical physics, optics, magnetism and electrochemistry. High-nuclearity clusters are of particular interest, because a transition from molecular to bulk metallic behaviour may be observed on increasing the cluster nuclearity size. However, general synthetic routes into such species are not widely known. Chapter 1 focuses on the synthesis of high-nuclearity ruthenium clusters and the reactivity of such species. The physical properties of these clusters are examined using a range of measurements, including cyclic voltammetry, IR and UV-vis-NIR spectroelectrochemistry, EPR and magnetic susceptibility studies. The chemistry of the high-nuclearity ruthenium cluster [RU{u2081}{u2080}({u03BC}-H)({u03BC}{u2086}-C)(CO){u2082}{u2084}]{u207B} is investigated in Chapter 2. The reactivity of this cluster towards a range of two electron donors is examined and the reaction kinetics of this reaction is investigated. Detailed spectroelectrochemical studies of the related clusters [RU{u2081}{u2080}({u03BC}-H)({u03BC}{u2086}-C)(CO){u2082}{u2084}]{u207B}, [RU{u2081}{u2080}({u03BC}{u2086}-C)(CO){u2082}{u2084}]{u00B2}{u207B} and [RU10({u03BC}-H)({u03BC}{u2086}-C)(CO){u2082}{u2083}(PPh{u2083})]{u207B} are also conducted. The final chapter (Chapter 3) covers the synthesis of a number of pentanuclear, hexanuclear and octanuclear mixed-metal clusters. The electrochemical behaviour is examined by cyclic voltammetry and spectroelectrochemistry and the linear and nonlinear optical properties of these clusters are assessed.