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-diphenylphosphino)ethane (L) as phosphorus and nitrogen donors ligand have been synthesized. Complex 1 has been characterized by single-crystale determinationas a centrosymmetric dihalide bridged binoclear complex of general formula [LCu(μ-X)2CuL] in space group P21/n with a = 9.046(2), b = 16.144(2) and 12.754(4) Å, β = 93.68(2)°, Z = 2. Both phosphorus and nitrgoen are coordinated to copper which is tetra-coordinated. The CuN bond distance is partivularly long (2.2878(2) Å) and greatly exceeds the sun of the covalent radii. Complex 2 has been only identified by chemical analysis, mass spectra and NMR spectroscopy. These data allow us to propose the [L2Cu]PF6 formula, with two ligands bonded to copper in a chelating mode by phosphorus and nitrogen.