Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589062
Title: Chemistry of the terminal pnictogen complexes of lead, tin and germanium
Author: Harris, Lisa Ann Marie
Awarding Body: University of Sussex
Current Institution: University of Sussex
Date of Award: 2013
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Abstract:
A series of tin(II) and lead(II) β-diketiminate amides [(BDI)MNRR'] (BDI = [CH{(CH3)CN-2,6-iPr2C6H3}2]; M = Sn, Pb; RR' = iPr2, H(2,6-iPr2-C6H3), H(2-iPr-C6H4), H(C6H5)) were synthesised and characterised. The reactivity of [(BDI)MN(iPr)2] and [(BDI)MNH(2,6-iPr2-C6H3)] towards aliphatic electrophiles, heterocumulenes and acids was investigated. The lead systems were found to be more reactive than the tin systems and the amide ligand was found to be more reactive than the anilide ligand. In general, the [(BDI)MNRR'] systems under investigation displayed the expected nucleophilic and basic behaviour. For instance, treatment of [(BDI)SnNH(2,6-iPr2-C6H3)] with methyl triflate resulted in the formation of [(BDI)SnOSO2CF3]. However, addition of phenyl isocyanate to [(BDI)MNRR'] (M = Sn, Pb; RR' = iPr2, H(2,6-iPr2-C6H3)) resulted in the formation of a bis-β-diketiminate complex, [(BDI)M(OC{=NPh}C{=C(Me)CN(H)(Ar)}(C{Me}=CN(Ar)})], a net result of nucleophilic addition to the electrophilic carbon in phenyl isocyanate by the γ-carbon in the BDI backbone. DFT studies were undertaken to rationalise the reactivity. The reactivity of group 14 metal β-diketiminate phosphide complexes [(BDI)MPR2] (BDI = [CH{(CH3)CN-2,6-iPr2C6H3}2]; M = Ge, Sn, Pb; R = C6H11, C6H5) towards selenium and tellurium was examined. For the tin(II) and lead(II) systems, no reactivity was observed upon addition of one or five equivalents of tellurium. In contrast, the germanium(II) systems exhibited unexpected reactivity with selenium and tellurium, where one equivalent of the chalcogen resulted in its insertion into the germanium-phosphorus bond, [(BDI)GeEPR2] (E = Se, Te), and five equivalents of selenium resulted in a further coordination of a selenium to the phosphorus, [(BDI)GeSeP(Se)R2]. DFT studies were undertaken in order to rationalise this behaviour. Lastly, the process of aerosol-assisted chemical vapour deposition (AACVD) was undertaken on some of these group 14 metal chalcogenide complexes in order to probe their suitability as a single source precursor (SSP) for thermo-electric materials.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.589062  DOI: Not available
Keywords: QD0146 Inorganic chemistry
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