Tetrakis(sulfurdiimido)silane, -germane and -stannane

Z. Naturforsch. 53 b, 573-580 (1998); received March 30, 1998 Silicon, Germanium, Tin, Sulfur Diimides, Heterocycles, NMR Data Two tetrakis(sulfurdiimido)silanes [Si(NSNR)4 (R = rBu la, SiMe3 lb)], two germanes [Ge(NSNR)4 (R = rBu 2a, SiMe3 2b)] and one stannane [Sn(NSN?Bu)4Sn 3a] were prepared and characterised by 'H, l3C, i5N, 29Si and ll9Sn NMR spectroscopy in solution, and 3a was also studied in the solid state by 1 l9Sn CP/MAS NMR. Whereas la,b and 2a,b are monomeric in solution, the 119Sn NMR data suggest that 3a is associated both in solution and in the solid state, and that the tin atoms are hexa-coordinated. The attempted stepwise synthesis of la by using one, two, three or four equivalents of K[(NSN)rBu] led to mixtures of la with Cl3Si(NSNrBu) 4a, Cl2Si(NSN/Bu)2 5a, and ClSi(NSNfBu)3 6a. Only one sulfurdiimido ligand of the silane la reacted with hexachlorodisilane by oxidative addition and cleavage of the Si-Si bond to give the new heterobicyclic derivative 7a which is held together by two different coordinative N-Si bonds.