Distortion of cyclopentadienyl rings in μ 5-c cyclopentadienyl-palladium complexes: Crystal structures of [Pd(C 5H 5)Cl(PMe 2Ph)] and [Pd(C 5H 5)(Ph 2PCH 2CH 2PPh 2)][PF 6

Abstract

The structures of [Pd(C 5H 5)Cl(PMe 2Ph)] and [Pd(C 5H 5(dppe)]PF 6(dppe  Ph 2PCH 2CH 2PPh 2) have been determined by X-ray analysis. Both are μ 5-cyclopentadienyl compounds, with the Cp ring nearly perpendicular to the PdPCl or PdP 2 plane. Comparison of their molecular geometries with those of other cyclopentadienyl-palladium complexes of the types PdCpLL′ and PdCpL 2 reveals the existence of a complete range of ring-PdLL′ or ring-PdL 2 orientations and suggests that the usual assignment of structures of these types as either staggered or eclipsed is not realistic. Likewise, the patterns of long and short CC bonds of the Cp rings do not in general follow the sequences expected for the idealized geometries, although large librational distortions of the C 5H 5 rings in most of the compounds limit the accuracy of these determinations. The lengths of the PdC(Cp) bonds appear to be much more dependent on the relative trans influences of L and L′ than on the ring orientations.