Synthesis and characterization of bis(diphenylphosphinomethyl)amino ligands and their Ni(II), Pd(II) complexes: Application to hydrogenation of styrene

Abstract

Transition metal complexes of Ni(II) and Pd(II) with ditertiary bis(diphenylphosphinomethyl)amino ligands, (Ph2PCH2) 2NC(CH3)3 (1) and [(Ph2PCH 2)Nm-PhSO3]Na (2) (Ph = phenyl), have been synthesized in good yields under nitrogen atmosphere by Schlenk technique. All complexes have been characterized using elemental analyses and spectroscopic techniques such as atomic absorption, FT-IR, and NMR (1H, 31P). Atomic absorption spectroscopic analysis showed that the reactions of ligands 1 and 2 with NiCl2·6H2O and [PdCl2(COD)] occurred in 1:1 molar ratio. The metal complexes [NiCl2(Ph 2PCH2)2Nm-PhSO3Na] (4) and [PdCl2(Ph2PCH2)2Nm-PhSO 3Na] (6) were found to be soluble in ethanolic and aqueous solutions, as well as slightly soluble in water. Electrochemical behaviors of complexes were investigated by cyclic voltammetry. Catalytic effects of Pd(II) complexes were tested throughout the hydrogénation of styrene to ethylbenzene. © 2008 Wiley Periodicals, Inc.