PREPARATION AND CHARACTERIZATION OF TRIS(TRIMETHYLSILYL)SILYL DERIVATIVES OF TIN - X-RAY CRYSTAL-STRUCTURE OF CL2SN[SI(SI(CH3)3]2

Six new [tris(trimethylsilyl)silyl]tin(IV) compounds, R4-xSn[Si(SiMe3)3]x (R = Me, x = 1, 2; R = n-Bu, x = 1, 2; R = Cl, x = 1, 2) have been prepared and characterized, including 1H, 13C, 29Si, and 119Sn NMR spectra, which were consistent with the expected structures. An X-ray structure determination of Cl2Sn[Si(SiMe3)3]2 revealed a pronounced distortion of the tetrahedral geometry around tin induced by the large steric requirements of the Si(SiMe3)3 groups. Crystals of C18H54Cl2Si8Sn were monoclinic, C2/c, with a = 16.050 (4) Å, b = 10.014 (2) Å,c = 47.289 (10) a, β = 90.17°, V = 7600 Å3, and Z = 8. The compound was more stable toward atmospheric moisture than comparable organotin dichlorides. Attempts to make the germanium analogue of the dichlorostannane via reaction of GeCl4 with 2 equiv of (THF)3LiSi(Si(CH3)3)3 gave the dimer [Cl2GeSi(SiMe3)3]2 instead. © 1990, American Chemical Society. All rights reserved.