THE FORMATION AND MOLECULAR STRUCTURE OF BIS(η5-CYCLOPENTADIENYL)BIS(PENTAFLUOROPHENYL)VINYLENEVANADIUM: AN ACETYLENE DERIVATIVE OF VANADOCENE

Article abstract of DOI:10.1016/S0022-328X(00)93567-8

A reaction between vanadocene and bis(pentafluorophenyl)acetylene in benzene solution has produced the title compound, (η⁵-C5H5)2V<η²-C2(C6F5)2>, in 66percent yield.The product has been characterized by infrared, mass spectral, and electron spin resonance data, as well as by a single crystal X-ray diffraction study.The compound crystallizes in the monoclinic space group C2/c with a=11.961(6), b=10.010(5), c=16.670(8) Angstroem, β=98.42(5)^o, and ρ_calc=1.81 g cm^-3 for Z=4.Least-squares refinement based on 984 observed reflections led to an R value of 0.039.The molecule resides on a crystallographic two-fold axis.The V-C(η²) bond length is 2.077(5) Angstroem, while the V-C(η⁵) distances range from 2.268(6) to 2.291(5) Angstroem and average 2.282(8) Angstroem.Within the acetylenic ligand the C<*>C length is 1.269(9) Angstroem, and the C<*>C-C(C6F5) angle is 142.3(4)^o.