Studies in the co-ordination chemistry of germanium and neighbouring elements

Abstract

In the first part of this thesis, the preparation of the known, compounds trans-(Et(_3)P)(_2)Pt(X)mC(_6)H(_4)F, and trans-(Et(_3)P)(_2)Pt(X)pC(_6)H(_4)F where X = C1, SnC1(_3) and of the new compounds trans-(Et(_3)P)(_2)Pt( GeC1(_3))mC(_6)H(_4)F and trans-(Et(_3)P)(_2)Pt(GeC1(_3))pC(_6)H(_4)F is described. Attempts to prepare further such compounds where X = SiMe(_3), GeBr(_3) were unsuccessful. The mass, infra-red, proton, magnetic resonance, fluorine magnetic resonance and X-ray photoelectron spectra of these compounds were recorded and the (^19)F n.m.r. and X-ray photoelectron spectra were used to investigate the trans-effect of the group IVb ligands, in these platinum-group IVb element complexes. In the first chapter the trans-effect theory is discussed. The second chapter is concerned with the experimental details and spectral data. The results obtained are discussed in the light of other evidence for the high trans-effect in platinum(ll)-group IVb compounds in Chapter 2. In Part II, the preparation of some methyleneamino derivatives containing groups R(_2)C:N- attached to silicon, germanium and phosphorus (R = t-butyl, p-tolyl, phenyl) is described. The new compounds prepared are [R(_2)C:N](_4) Ge, (R = phenyl, p-tolyl), [Bu(_2)(^t)C:N](_x) GeX(_4-x) (x = 1,2,3; X = Br, C1), and Me(_x)Si[N:C(p-tolyl)(_2)](_4-x) (x = 1,2) (Chapter 1) and P[N:CR(_2)](_3) (R = p-tolyl, phenyl), X(_2)P[N:CR(_2)] (X = C1, Ph; R = t-butyl, phenyl, p-tolyl) and OPC1(_x) (N:CR(_2))(_3-x') (R = t-butyl, p-tolyl, phenyl; x = 0,1,2) (Chapter 2). The mass, infrared and (^1)H nuclear magnetic resonance spectra were recorded and, for the phosphorus compounds the (^31)P n.m.r. spectra were recorded. These compounds were prepared with the object of finding model systems for the study of dative N=M π-bonding nitrogen and silicon, germanium and phosphorus. The shape (linear or bent) of the M-N-C skeletons (M = silicon,germanium and phosphorus) in these moisture sensitive methyleneamino compounds could not be unambiguously determined from the n.m.r. andinfrared spectral data obtained. The mass spectral data and molecular weight determination indicated the compounds to be in a monomeric state of association (^31)P n.m.r. data are discussed with reference to analogous isocyanate, isothiocyanate and amino derivatives of phosphorus, (Chapter 2).Attempts to prepare Bu(^t)(_2) C:NMe are described in Appendix 1 and experimental techniques, instrumentation and analytical methods are described in Appendices 2,3 and 4.