Über gemischte Bindungen in der IV. Hauptgruppe, II [1]. Hexacyclohexylethan-Analoga Pb2(c-Hex)6, (c-Hex)3Pb–Sn(c-Hex)3 und Sn2(c-Hex)6 / On Mixed Group IVb – Group IVb Bonds, II [1]. Hexacyclohexylethane Analogues Pb2(c-Hex)6, (c-Hex)3Pb–Sn(c-Hex)3, and Sn2(c-Hex)6

Abstract

(c-Hex)3Pb-Sn(c-Hex)3 is synthesized from (c-Hex)3PbLi and (c-Hex)3SnCl at -50 °C in THF. The three title compounds are isomorphous. The compounds have been investigated by mass, NMR and vibrational spectra. Pb2(c-Hex)6: highest fragment Pb2(c-Hex)5 +, 1J(13C-207Pb) 30.2 Hz. 2J(13C-207Pb) 9.1 Hz, δ(207Pb) +81 ppm. (c-Hex)3Pb-Sn(c-Hex)3: highest fragment PbSn(c-Hex)5 +, δ(207Pb) -92 ppm, δ(119Sn) -157 ppm, 1J(207Pb-19Sn) 2217 Hz. Sn2(c-Hex)6: parent peak Sn2(c-Hex)6 +, 1J(13C-119Sn) 113.3 Hz, 2J(13C - 119Sn) 26.4 Hz, δ(119Sn) -71 ppm, 1J(119Sn-119Sn) 1258 Hz, ν(Sn-Sn) 135 cm_1.The crystal structure of Pb2(c-Hex)6 has been deter­mined and refined to R = 0.044. The symmetry of the molecule is C3; distances Pb-Pb 287.6(4), Pb-C 226(2) and 228(3) pm. The cyclohexyl groups are unusual flat and distorted from the normal Cs symmetry; this is in accordance with two sets of 13C NMR signals in benzene-d6.