4-phenylthio-2-(triisopropylsilyl)but-2-enenitrile

C19H29NSSi, M(r) = 331.60, monoclinic, P2(1)/n, a = 10.428 (3), b = 24.094 (7), c = 16.197 (4) angstrom, beta = 98.50 (2)-degrees, V = 4025 (2) angstrom 3, Z = 8, D(x) = 1.09 g cm-3, Mo K-alpha, lambda = 0.71069 angstrom, mu = 2.15 cm-1, F(000) = 1440, T = 291 K, R = 0.053 for 3206 observed reflections. The E configuration about the double bond is established. The two independent molecules have a similar geometry. In each, the ethylenic system is essentially planar with deviations less than 0.020 angstrom from the best mean plane through C1, C2, C3, C4 and Si. To relieve the steric strain, the C(sp2)-Si bond [mean value 1.898 (5) angstrom] is stretched and some angles about the double bond deviate significantly from the ideal trigonal value.