X-Ray Studies on Pt/Re and Other Compounds

[摘要] In this thesis X-ray diffraction analysis is applied to the study of molecular structure and conformation. The contents are divided into four sections. The first section is a brief review of the theory and practical aspects of the X-ray diffraction methods used in sections two, three and four. Section two is concerned with the structure of ruthenium and platinum complexes stabilised by the diphosphine ligand Ph2PCH2PPh2 (dppm). First, earlier work on binuclear complexes, on triangular M3(dppm)3 species and on platinum cluster complexes is reviewed and the structure of the binuclear species [Ru2{mu- Cl)(mu-H)Cl2(CO)2}(mu-dppm)2] is described. Then the structures of five large heterometallic clusters derived from [Pt3{mu3-Re(CO)3}(mu-dppm)3]+ are presented. These clusters are obtained by reaction of the parent cluster with dioxygen, halide or neutral ligand. Their structures have been of critical importance to this new field of cluster chemistry. The characterisation of [Pt3(mu3-ReO3)(mu-dppm)3]+, which contains Pt(0) stabilised by phosphine and Re(VII) stabilised by oxide, is of particular significance. The section concludes with a summary of current knowledge of the chemistry of and bonding in platinum-rhenium clusters. Platinum-rhenium catalysts, for which the clusters are models, are also briefly described. Section three is concerned with the stereochemistry of newly synthesized organic compounds. The formation of oxazines by Diels-Alder addition of acylnitroso compounds is described in Chapter 3.1. The reaction typically involves the creation of chiral centres. The structural work has been directed at predicting the stereochemistry of the preferred diastereoisomer. In Chapter 3.2 the stereochemistry of Diels-Alder addition of ferrocene derivatives to 1,3-diphenylisobenzofuran is considered, with emphasis on the effect of AlCl3 catalysis on the nature of the product. In Chapter 3.3 the stereochemistry of cis and trans ArCH=CHAr molecules, and its relationship to their biological activity, is discussed. Section four describes the structure of tetramethoxycalix[4]arene silver(I) nitrate. The ability of calix[4]arenes to act as hosts has led to major developments in supramolecular chemistry. The attachment of silver(I) to the calixarene is of a novel type. The section also deals with the structures of mononuclear tungsten(II) complexes in which the metal atom could be six or seven co-ordinate.

[发布机构] University:University of Glasgow

[关键词] Molecular chemistry, Physical chemistry, Analytical chemistry, Inorganic chemistry