SYNTHESIS AND MOLECULAR-STRUCTURES OF TRIS[BIS(TRIMETHYLSILYL)METHYL]STANNANE AND THE CORRESPONDING STANNYL TRIFLATE

The reaction of bis [bis(trimethylsilyl)methyl] stannylene with calciu m metal yields tris[bis(trimethylsilyl)methyl]stannane 1, which can be reacted with trifluormethanesulfonic acid to tris[bis(trimethylsilyl) methyl]stannyl triflate 2. Due to, the intramolecular steric strain, t he CSnC angles are widened and for 2 a CSnC angle sum of 346.2 degrees is achieved. The flattening of the SnCSi2 moiety leads to remarkably small(-1) J(Si,C), (1)J(C,H) and (1)J(Sn,C) coupling constants. Crysta llographic data for 1: monoclinic, P2(1)/c, a = 1730.1(2), b = 1645.4( 3), c = 1230.6(3) pm, beta = 92.42(1)degrees, Z = 4, wR(2) = 0.1351); for 2: monoclinic, P2(1)/n, a = 1180.8(2), b = 1842.0(4), c = 1713.1(3 ) pm, beta = 93.89(2)degrees, Z = 4, wR(2) = 0.1430).