Synthesis and X-ray crystal structure of dipalladiumtetrachlorobis(ethyldipyrrolylphosphine)

The ligand ethyldipyrrolylphosphine and the corresponding palladium(II) complex, [PdCl{PEt(pyrrolyl)(2)}mu Cl](2), were synthesized. The X-ray single-crystal structure of this palladium complex was determined; it crystallizes in the monoclinic space group P2(1)/n with a = 15.347(7), b = 11.212(6), c = 17.355(5) Angstrom and beta = 115.72(3)degrees and contains a central pseudo square planar Pd2Cl4 ring having a trans conformation of N-pyrrolyl phosphines. The arrangement of the pyrrole substituents around the phosphorus atom in the complex clearly shows the inaccessibility of the alpha-carbon for polymerization. (C) 1999 Elsevier Science Ltd.