名称:
Synthesis and structures of the dinuclear tin(II) complexes [R=Ph, X(Z)=CPh; R=SiMe3, X(Z)=PPh2] and of related compounds
摘要:
Tin(II) compounds containing the ligands [CH(C6H3Me2-2,5)C(Bu-t)NSiMe3] ( L-1), [CH(Ph)C(Ph)NSiMe3] ( L-2), [CH(SiMe3)P(Ph)(2)NSiMe3] ( L-3), [CH(SiMe3)P(Ph)=NSi(Me)(2)C6H4-1,2](-) ( L-4), [C(Ph)C(Ph)NSiMe3](2) ( L-5), and [C(SiMe3)P(Ph)(2)NSiMe3](2) ( L-6) are reported: the transient SnBr(L-1) (1) and SnBr(L-2) (2), Sn(L-1)(2) (3) [P.B. Hitchcock, J. Hu, M.F. Lappert, M. Layh, J.R. Severn, J. Chem. Soc., Chem. Commun. (1997) 1189], the labile Sn(L-2)(2) (4), [Sn(L-5)](2) (5), SnCl(L-3) (6), Sn(L-3)(2) (7), [Sn(L-6)](2) (8), Sn(L-4)(2) (9) and Pb(L-4)(2) (10). They were prepared from (i) SnBr2 and K(L-1) (1, 3) or K(L-2) (2, 4, 5); (ii) SnCl2 and Li(L-3) (6-9); or (iii) PbCl2 and Li(L-4) (10). Each of 1, 3 and 5-10 has been characterised by multinuclear NMR spectra; 3, 5, 6, 8, 9 and 10 by EI-mass spectra, but only 3, 5, 8, 9 and 10 were isolated pure and furnished X-ray quality crystals. Of greatest novelty are the title binuclear fused tricyclic ladder-like compounds 5 and 8. Quantum chemical calculations, on alternative pathways to 5 from 2 and to 8 from 7, are reported. (C) 2009 Elsevier B.V. All rights reserved.