X-ray Diffraction Analysis of Organometallic Compounds with Catalytic Properties

[摘要] The study, by use of X-ray diffraction analysis, of the structures of organometallic complexes with catalytic properties has proved to be of great importance in understanding the chemistry of catalytic processes. It is this technique that has been vital in determining the structures of the complexes reported in this thesis. The thesis is divided into three sections. Section 1 discusses the structural features of new dppm-stabilised triplatinurn complexes derived from the parent cluster [Pt3(CO) (dppm)3]2+ (dpprn = Ph2PcH2PPh2). The structural work was carried out to determine how closely Pt3 clusters could model the behaviour of similar Pt3 species which occur on platinum surfaces. The new complexes are derived by chemical modification of the M3(dppm)3 nucleus which is unusually stable to fragmentation into species containing one or two metal atoms. The structure analyses reported here have been of critical importance in the development of this new field of cluster chemistry. Brief reviews on binuclear dppm complexes and on platinum cluster chemistry have been carried out and earlier work on M3 (dppm) 3 species is also reported. A brief analysis on the conformations of the dppm ligand has also been carried out. The work reported in Section 2 relates to the addition of an alkyne to the complex [CpM(SR) (hfb)2], where M = Mo or W, Cp = eta5-C5H5, R = an alkyl or aryl group and hfb = F3CC5CCF3. The products of this reaction can adopt at least twelve different structural forms. The form isolated depends on several factors including the natures of the thiolato substituent R, of the metal atom and of the incoming ligand. This work is directed to enhancing our in understanding of transition metal catalysed oligomerisation and polymerisation reactions of alkynes. The structures of other related products are also reported including those of the thermolysis reaction of a [CpM(SR) (hfb)2] complex and those of the addition of ligands other than alkynes to the starting complex. Reported in Section 3 are three unrelated structure analyses. The sulphimide complex of palladium is of interest because of its similarity to cis-[PtC12(NH3)2], a chemotherapeutic but toxic compound. [Ru(SC(NH2)2)6] [CF3SO3]2 is the first characterised thiourea complex of ruthenium(II). Its structure was determined because the mode of attachement of thiourea to the ruthenium was unclear. A pilot study of electron deformation density analysis is also reported. Two data sets were collected for C4Cl4O2s, one at 295K the other at 150K using profile analysis of the Bragg reflections. Although the data did not lead to a satisfactory deformation density the analysis gave a clearer picture of the experimental and computational requirements for such work.

[发布机构] University:University of Glasgow

[关键词] Analytical chemistry, Inorganic chemistry