Nickel(II) complexes containing thiosemicarbazone and triphenylphosphine: Synthesis, spectroscopy, crystallography and catalytic activity

Four new Ni(II) complexes of the general formula [Ni(PPh3)(L)](L = dibasic tridentate ligand derived from 4-diethylamino-salicylaldehyde and thiosemicarbazide or 4-N-substituted thiosemicarbazide) have been reported. The new complexes have been synthesized and characterized by analytical and spectroscopic (IR, electronic, H-1 NMR and P-31 NMR) techniques. Molecular structure of one of the complexes has been determined by X-ray crystallography. The complex. [Ni(PPh3)(L4)] (H(2)L4 = thiosemicarbazone prepared from 4-diethylamino-salicylaldehyde and 4-phenylthiosemicarbazide) crystallized in monoclinic space group with two molecules per unit cell and has the dimensions of a = 13.232(6) angstrom, b= 10.181(5) angstrom, c = 13.574(7) angstrom, alpha = 90 degrees, beta = 98.483(2)degrees and gamma =90 degrees. Catalytic activity of the complexes has been explored for aryl-aryl coupling reaction. (C) 2011 Elsevier B.V. All rights reserved.