Bis-homoleptic, Terdentate, Cyclometalates of Group 8 and 9

Rees, Thomas Wheildon (2017). Bis-homoleptic, Terdentate, Cyclometalates of Group 8 and 9. University of Birmingham. Ph.D.

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Abstract

Cyclometalates have been the focus of much attention in recent years and have applications ranging from photovoltaics to cancer therapies. Many heteroleptic terdentate complexes are known in the literature however bis-homoleptic terdentate cyclometalates remain rare. The metals of group 8 and 9 are of particular interest due to the excellent optoelectronic properties of their organometallic complexes. In this work our initial focus was the synthesis of a novel series of substituted phenylbipyridine ligands. These complexes were characterised by UV-Vis absorption and cyclic voltammetry and found to be suitable for use in photovoltaic devices. Selected complexes were tested in dye-sensitized solar cells with the best device achieving an efficiency of 4.30%. We next turned our attention to the synthesis of a second generation of ligands. This included 2,2’,6’,3’’terpyridines, a pyrimidylbipyridine and a 2-quinolyl-6-phenylpyridine. This work allowed access to a second generation of ruthenium complexes which were characterised by UV-Vis absorption spectroscopy and cyclic voltammetry. The third area on which we concentrated was further expansion of the series of complexes by variation of the metal centre. Initial work with osmium gave bis-homoleptic terdentate complexes with very broad absorption profiles. The data obtained was used to explore the effect of spin-orbit coupling on the optoelectronic properties of such complexes. Heteroleptic bis-cyclometalates of iridium were synthesised and characterised by UV-Vis absorption and emission spectroscopy. Finally, preliminary investigations into the synthesis of bis-homoleptic terdentate cyclometalates of iron, rhodium and cobalt were undertaken.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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