SYNTHESIS AND OXIDATION CATALYSIS OF HETEROBIMETALLIC SYSTEMS

Abstract

Two different chemical systems ,namely the homo- and heterometallic systems derived from the hemilabile 2-aminophosphinethiazole ligand, and the homo-and heterometallic magnetically recoverable PVP-stabilized iron oxide-supported gold nanoclusters, were studied. The underlying theme is the construction of bi- and heterometallic assemblies through different uses of ligands. This work was carried out with the objective of deciphering the structures of these complexes and to understand how they are formed, as well as to attempt to form an environmentally-friendly oxidation catalyst.

This thesis is divided into four chapters. An overview of the need for improvements in oxidation catalysis is given in Chapter One. The discussion is focused on the significance of the need for new catalysts, as well as the features of sulfoxidation, alcohol oxidation and gold-based CO oxidation catalysts. The objective and scope of the study are given in the final section of Chapter One.

Chapter Two describes the synthesis and coordination chemistry of the hemilabile 2- aminophosphinothiazole and diphenylphosphanyl-thiazolidine-2-thione. The products of the reaction were mostly decomposition products due to the instability of the ligands mentioned above. Nanomaterials of Au-In and Ag-In have been tested for their catalytic activity in sulfoxidation of tetrahydrothiophene.

Chapter Three discusses the results on the synthesis and structural characterization of magnetically recoverable PVP-stabilized iron oxide-supported gold nanoclusters. Oxidation of alcohols by these nanocomposites was also carried out and the results discussed within.

The important findings are summarized in Chapter Four. Some suggestions are given on the solutions to the problems encountered and future direction of this work.