Bis[tris(trimethylsilyl)silyl]zink, -cadmium und -quecksilber,schwingungsspektroskopische Daten und Strukturanalysen

Bis[tris(trimethylsilyl)silyl] Zinc, Cadmium, and Mercury – a Structural Study by IR and Raman Spectroscopy and X-Ray Analyses Raman and FT-IR spectra of bis[tris(trimethylsilyl)silyl] zinc ( 1 ), cadmium ( 2 ) and mercury ( 3 ) were recorded. The vibrational data are in agreement with either D_3h or a D_3d symmetry. The latter had been shown to be the correct one at least for the solid state by X-ray diffraction experiments. All three compounds crystallize isomorphically in the triclinic centrosymmetric space group P1 . [ 2 (T = 293 K): a = 9.4388(11); b = 9.744(2); c = 12.926(2); α = 68.200(12); β = 71.971(10); γ = 60.925(10); Z = 1; (T = 173 K): a = 9.336(6); b = 9.585(5); c = 12.488(8); α = 68.77(4); β = 72.28(4); γ = 62.06(4); 3 : a = 9.467(2); b = 9.749(2); c = 12.885(2); α = 67.840(14); β = 71.510(14); γ = 60.890(14); Z = 1]. The Hg—Si bondlength in 3 was found to be 246.9(2)pm, somewhat shorter then in all disilylmercury derivatives investigated sofar and even shorter than the Cd—Si bond in 2 (250.4(1)pm). Bondlengths and angles within the tris(trimethylsilyl)silyl group are virtually equal in all three group 12 derivatives and lie in the expected range.