Crystal structures of trans-[Mo(CO)4(PPh3)2] and 1,4-bis(diphenylphosphino)-2,5-difluorobenzene

Article abstract of DOI:10.1016/S0020-1693(96)05133-X

Thermolysis of [{Mo(CO)₄(μ-DPFB)}₂] (DPFB=1,4-bis(diphenylphosphino)-2,5-difluorobenzene) in acetonitrile followed by addition of triphenylphosphine yields trans-[Mo(CO)₄(PPh₃)₂] and free DPFB which co-crystallise. Crystal data: triclinic, space group P1, a=9.4976(20), b=10.0708(21), c=16.1178(29) A, α=100.333(16), β=101.741(15), γ=94.445(17)°, V= 1474.48 A³,Z=1. Only half of each molecule is unique, being related to the second by the inversion centre. In trans-[Mo(CO)₄(PPh₃)₂], little deviation from ideal octahedral geometry is seen and the Mo-P bond length of 2.500(1) A is significantly shorter than those found in the cis isomer (F.A. Cotton, D.J. Darensbourg, S. Klein and B.W.S. Kolthammer, Inorg. Chem., 21 (1982) 294).