Date of Award

2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Environmental Science

First Advisor

Assefa, Zerihun

Abstract

Volatile organic compound(s), VOC(s), detection have become a highly demanding area of research due to potential harmful effects to the ecosystem. The search for methods of VOC sensor devices has led to the examination of photoluminescence and photoluminescent materials such as metal complexes. Their luminescent properties markedly with phosphine and/or nitrogen based ligands, bridging ligands, have the ability to accommodate metal atoms with short metal – metal distances. It is of great interest to accomplish short metal interactions as the photoluminescent properties can be altered. We show the synthesis and structural characterization of the bridging ligand, 1-methylbenzimidazole diphenylphosphine. We examined the coordination mode of this ligand to gold (I) and silver (I) metals. The structure of the mononuclear gold (I) complex, a gold (I) dimer, as well as a silver (I) dimer complex were observed in non-polymeric form with notable differences around the metal center. It was also shown the bringing together of two silver dimers by a second bridging ligand, diphenylphosphonic acid, to form a silver tetranuclear complex. The electronic properties of the ligand and metal complexes were also described. The tetranuclear complex displayed temperature dependent photoluminescence when excited by long-wave radiation. Finally, we explored the sensitivity of the dimer gold (I) complex to acetonitrile. Here, we show the synthesis, X-ray crystallography, characterization, and photoluminescence of the ligand, mononuclear complex, dimers of gold (I) and silver (I) complexes, and the tetranuclear complex.

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