SYNTHESIS AND PHYSICAL STUDIES OF COPPER(I) COMPLEXES WITH THE AMBIDENTATE LIGAND (1-PIPERIDYL-2-DIPHENYLPHOSPHINO)ETHANE - X-RAY STRUCTURAL CHARACTERIZATION OF A COPPER(I) DIMER

Copper(I) complexes with (1-piperidyl-2-diphenyIphosphinc)ethane (L) a s phosphorus and nitrogen donors ligand have been synthesized. Complex 1 has been characterized by single-crystal structure determination as a centrosymmetric dihalide bridged binuclear complex of general formu la [LCu(mu-X),CuL] in space group P2(1)/n with a = 9.046(2), b = 16.14 4(2) and c = 12.754(4) Angstrom, beta = 93.68(2)degrees, Z = 2, Both p hosphorus and nitrogen are coordinated to copper which is terra-coordi nated, The Cu-N bond distance is particularly long (2.288(2) Angstrom) and greatly exceeds the sum of the covalent radii. Complex 2 has been only identified by chemical analysis, mass spectra and NMR spectrosco py. These data allow us to propose the [L2Cu]PF6 formula, with two lig ands bonded to copper in a chelating mode by phosphorus and nitrogen. (C) 1998 Elsevier Science S.A.