Some Reactions of Cobalt Carbonyl Complexes in Solution

Leslie, Alison Elizabeth (1981) Some Reactions of Cobalt Carbonyl Complexes in Solution. PhD thesis, University of Glasgow.

Abstract

The aim of this research was to further the knowledge and understanding of the reactions of dicobalt octacarbonyl. This subsequently has been split into four main areas. Initially investigation into the formation of the anion tetracarbonyl cobaltate (-1), [Co(CO)4]- , using a range of halide salts and lithium salts as the disproportionating reagent, and in different solvents and atmospheres, was undertaken. An abortive attempt at studying the kinetics of this reaction was made. On discovering the complexity of reaction when diethyl ether was the solvent, the next set of experiments were concerned with the reduction of Co2(C0)8 in ethereal solvents using sodium amalgam. This proved to be no less complicated, showing that an intermediate complex, [Co3(CO)10]- , persisted in solution. In diethyl ether the not inconsiderable effect of the cation on [Co(CO)4]- was demonstrated by the shift of i. r. absorption frequency, and the line shape, of the anion. Further research into the interaction of mercury containing species and Co2(CO)8 provided a series of mercury - cobalt carbonyl anions, of the form {Hg [Co(CO)4}- (X = Cl, Br or Co(CO)4), being isolated as the [ M(ophen)3]2+ (M = Fe, Ni) derivatives. The ratio of the different species isolated in the solid form depended on the solvent used in the experiment and the metal ion in the phenanthroline derivative. To elucidate the nature of certain mysterious species present in reactions of Co2(CO)8 with disproportionating reagents a series of experiments involving Co2(CO)8, Co4(CO)12 and [Co(CO)4]- (in varying amounts) were conducted. Those involving Co2(CO)8 and Co4(CO)12 only showed the large effect on the i. r. spectrum (terminal carbonyl region) that trace amounts of one of the reactants can wield. Hence it was deduced that the variation in i. r. spectra observed were not due to a new complex but due to the interactions of species already present in solution. Finally two isolated pieces of research have been noted. The first involved preparation of CoBr2 (etherate)x compounds in the solid form and studying the U. V. / visible spectrum, in both the solid and solution phases, to derive the coordination of Co2+ . The other item of work was the preparation and characterisation of [Ph4P] + [Co(CO)4]- , a new solid form of the anion. The reactions of this compound were looked into in conjunction with other sections of the research.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Inorganic chemistry
• Date of Award: 1981
• Depositing User: Enlighten Team
• Unique ID: glathesis:1981-77178
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jan 2020 09:17
• Last Modified: 14 Jan 2020 09:17
• URI: https://theses.gla.ac.uk/id/eprint/77178