Crystal and molecular structure of η-cyclopentadienyl[1,3,4-η-(1,2-dimethoxycarbonyl-5,5,5-trifluoro-3-trifluoromethylpent-1,3-dienyl)] triphenylphosphineruthenium. An unexpected reaction product from hexafluorobut-2-yne and a vinylruthenium complex

Abstract

Crystals of [[graphic omitted]C(CF₃)H(PPh₃)(η-C₅H₅)] are triclinic, space group, P, with Z= 2 in a unit cell of dimensions a= 9.353(4), b= 16.346(16), c= 10.875(6)Å, α= 93.82(7), β= 113.07(4), γ= 94.26(6)°. The structure has been solved by conventional heavy-atom methods from 4 184 diffracted intensities measured on a diffractometer and refined by block-matrix least-squares to R 0.039. The skeleton of the vinylruthenium complex remains intact, but the chain is extended by σ-addition of one molecule of hexafluorobut-2-yne with subsequent π-bonding of this acetylene to the ruthenium atom to form a cyclic system, [graphic omitted]C(CF₃)H. The co-ordination around the ruthenium atom is approximately octahedral, three sites being occupied by the η⁵-cyclopentadienyl ring and one by the triphenylphosphine ligand.