Reaction of a Stable Silylene with Divalent Group 14 Compounds

Abstract

The reaction of the stable silylene 1 (L′Si:) with CO, SnCl2, PbCl2, the stable carbene L′C: (2) and the stable germylene L′Ge: (3) was investigated as a possible approach for the synthesis of hetero-polysilanes (poly-carbosilanes, poly-germasilanes, poly-stannasilanes). The silylene 1 was found to be inert towards all substrates except SnCl2 and PbCl2. Reaction with SnCl2 led to the formation of the yellow, tris(silyl)stannane [(L′SiCl)3SnCl] (5) and elemental tin. The photolabile (5) was characterized by multinuclear NMR (1H, 13C, 29Si, 119Sn) and single crystal X-ray diffraction: C30H60Cl4N6Si3Sn, M = 849.60, orthorhombic, space group Pca21. The bond angles of 115.89 ° (ave. Si–Sn–Si) and 101.87 ° (ave. Cl–Sn–Si) show a slightly flattened tetrahedral geometry around the tin atom. – Thermolysis of 5 at 100 °C led to the deposition of thin films of tin; photolysis resulted in the formation of tin powder. All thermolysis products could be isolated and were characterized as SnCl2, elemental tin, L′Si: (1), L′SiCl2 (6) and the new disilane L′Si(Cl)-(Cl)SiL′ (7). Photolysis led to a reduced product spectrum (formation of Sn + SnCl2 + 7). Reaction of 1 with PbCl2 gave elemental lead and L′SiCl2 as the only products.