FOUR- AND FIVE-COORDINATE NICKEL(II) COMPLEXES OF THE ALIPHATIC, TRIDENTATE LIGANDS BIS(3-DIMETHYLARSINOPROPYL)METHYLARSINE AND BIS(3-DIMETHYLARSINOPROPYL)PHENYLPHOSPHINE

Abstract

Abstract Fifteen diamagnetic nickel(II) complexes of the flexible, tridentate ligands bis(3-dimethylarsinopropyl)phenyl-phosphine(dap) and bis(3-dimethylarsinopropyl)methylarsine(tas) were isolated and characterized. The molecular, five-coordinate complexes Ni(ligand)X 2 (ligand=dap; X=Cl, Br, I, NCS, CN: ligand=tas; X=Br, I, NCS, CN) and the four-coordinate complexes [Ni(dap)Cl]ClO4 and [Ni(dap)NO3]NO3 were studied by electronic and infrared spectra, magnetic, conductivity, and molecular weight measurements. On the basis of X-ray structural determinations of Ni(tas)Br2 and Ni(dap)(CN)2·H2O and the similar electronic spectra of the dap and tas series of complexes, the inner coordination geometry of all these complexes can be represented as a distorted square pyramid. The method of isolation and the properties of the polynuclear complexes [Ni2L3(H2O](ClO4)4 (L=dap and tas) and [Ni3(dap)3I5]B(C6H5)4 are also discussed.