Abstract The preparation of eight bis(pentaflurophenyl) complexes of Pd 11 and of Pt 11 with monodentate and bidentate nitrogen-donor ligands is described together with a preparation of a Pd 11 complex of 1,2-bis(diphenylphosphino)ethane. Some properties of the complexes are given. New possibilities for assignment of cis or trans configuration are discussed which depend upon the splitting or disappearance of certain bands in the IRspectra.