Planar tetracoordinate carbon stabilized in a dimetallic hafnium/aluminium compound: Formation and crystal structure of Cp 2Hf[μ-η 1 : η 2-MeCC(C 6H 11)][μ-CC(C 6H 11)]A1Me 2

Abstract

The reaction of [Me 2AlCCR] 2, 1 (R = cyclohexyl), with an equimolar quantity of Cp 2HfMe 2, 2 gave the dimetallic mixed metal complex Cp 2Hf(μ-η 1 : η 2-MeCCR)(μ-CCR)AlMe 2, 3 and trimethylaluminium. An X-ray diffraction study of 3 revealed that it has a planar tetracoordinate carbon atom (C3) bridging between hafnium and aluminium. The four bond distances in the central plane to C3 are 1.280(9) [C3 C1], 1.562(8) [C3C4], 2.091(6) [C3A1], and 2.432(6) [C3Hf] Å.