A TRIMERIC, CHAIR-SHAPED ZINC DIALKYLPHOSPHINE COMPLEX - SYNTHESIS AND STRUCTURE OF ([ZN(ET)(MU-PCY2)]3.THF).2THF [CY = CYCLOHEXYL (C6H11)]

Metalation of dicyclohexylphosphine (Cy2PH) with ZnEt2 (1:1 equiv) in THF gives a trimeric zinc dialkylphosphine complex {[Zn(Et)(mu-PCy2)]3.THF}. 2THF (1), which has been characterized by elemental analyses, H-1 NMR, P-31 NMR, and IR spectroscopic data and by a low temperature X-ray structural study. The complex crystallizes in the triclinic space group P1 (No. 2) with cell dimensions a = 13.059(3) angstrom, b = 13.889(3) angstrom, c = 18.635(3) angstrom, a = 75.98(3)-degrees, beta = 85.45(3)-degrees, gamma = 64.37-(3)-degrees, V = 2955.4(11) angstrom3, and Z = 2. The complex has a chair-shaped Zn3P3 core in which only one tetrahedral Zn center is coordinated by THF and the other two planar Zn centers are three coordinate. Two uncoordinated THF molecules reside in the lattice of 1. The title compound is a rare example of a zinc dialkyl- or diarylphosphine complex and the first such trimeric complex.