thesis

Studies in the organonitrogen chemistry of tin and neighbouring elements

Abstract

This thesis describes the preparation and properties of some new organonitrogen derivatives of silicon, germanium, and tin. The structural implications of their I.R., (^1)H-NMR. , and mass spectra are discussed with X-ray crystal structures in some cases. A survey of species containing tin-nitrogen bonds, and a discussion of the stereochemistry of tin are also presented. New methyleneamine derivatives of the type (R(_2)CN)(_n)Sn(^IV)C1(_4-n)(n = 2-4), (Ph(_2)CN)(_2)GeC1(_2), [(R(_2)CN)(_2)Sn(^11)](_n),(Ph(_2) CNSn(^11)c1)(_2), and Li(^t)Bu(_2)CN)(_3)Sn(^11) were prepared from the metal chlorides and N-lithioketimines. The adducts Ph(_2)CNH.Sn(^11)Cl(_2), ((^t)Bu(_2)CNH)(_n)Sn(^IV)Cl(_4) (n = 1,2), Ph(_2)CNH. (Ph(_2)CNSn(^11)Cl)(_2). C(_7)H(_8), and (^t)Bu(_2)CNH. (^t)Bu(_2)CNSn(^11)(_2)C1(_3) are described. Attempts to prepare (^t)Bu(_2)CNSn(^IV) led to (^t)BuCN and Sn(^11)Cl(_2). Similar decomposition of ((^t)Bu(_2)CN)(_n)Sn(^IV)c1(_4-n) (n = 2,3) 2,3) led to the imino-tin(II) complexes (^t)Bu(_2)CNH. (^t)Bu(_2)CNSn(_2)(^11)Cl(_3) and (^t)Bu(_2)CNH(_2)(^+). ((^t)Bu(_2)Sn(_3)(^11)C1(_5)(^-). The new M(^IV) derivatives are monomeric, except for the iminotin chlorides [(ph(_2)CN)(_n)Sn(^IV)C1(_4-n)](_m)(n = 2,3; m ≥ 2). The Sn(^11) derivatives are mostly di- or oligomeric, containing three-coordinate tin. Association appears to involve bridging methyleneamino groups. The adducts R(_2)CNH. (R(_2)CN)(_n)Sn(_2)(^11)C1(_4-n) to contain one three-coordinate and one four- coordinate tin atom. The C=N-M skeletons of those compounds containing terminal methyleneamino groups are probably bent with little or no N→M (p→d) π-bonding

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