X-RAY CRYSTAL-STRUCTURE AND THEORETICAL-STUDY OF TRIS(2,3-DIMETHYL-1,3-BUTADIENE)MOLYBDENUM(0)

Tris(2,3-dimethyl-1,3-butadiene)molybdenum(0), (C6H10)3Mo, crystallizes in the triclinic space group P1BAR with a = 9.554 (2) angstrom, b = 12.312 (2) angstrom, c = 7.060 (2) angstrom, alpha = 97.66 (2)-degrees, beta = 90.38 (2)-degrees, gamma = 99.07 (1)-degrees, V = 812.5 angstrom 3, Z = 2, D(x) = 1.375 g cm-3, F(000) = 359.91, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 7.50 cm-1, and T = 291 K. Final R = 0.0226 for 2873 unique observed [F0 > 2-sigma-(F0)] X-ray diffractometer data. The molybdenum atom is surrounded by the six equidistant terminal carbon atoms of three 2,3-dimethyl-1,3-butadiene ligands in a trigonalprismatic geometry. The ligands are all cisoid. The internal C-C bond lengths are slightly shorter than the terminal C-C bond lengths of the ligands in the complex. The bonding and structure of the complex were confirmed by extended Hukel molecular orbital calculations.