Ruthenium and palladium complexes incorporating amino-azo-phenol ligands: Synthesis, characterization, structure and reactivity
作者:Poulami Pattanayak、Sankar Prasad Parua、Debprasad Patra、C.-K. Lai、Paula Brandão、Vitor Felix、Surajit Chattopadhyay
DOI:10.1016/j.ica.2015.02.002
日期:2015.4
The ligands 2-((2-aminophenyl) diazenyl) phenol, HOL1-NH2, 1a; 2-((2-aminophenyl) diazenyl)-5-methylphenol, HOL2-NH2, 1b; and 2-((2-aminophenyl) diazenyl)-5-chlorophenol, HOL3-NH2, 1c, which are abbreviated as HOL-NH2, 1, afforded the complexes of compositions [(OL-NH) Pd(PPh3)], 2, and [(OL-NH)Ru(CO)(PPh3)(2)], 3, upon reaction with Na2PdCl4 and Ru(CO)(3)(PPh3)(3) respectively. In all the complexes the metals ions, Pd(II) or Ru(II), are coordinated by deprotonated ligand (OL-NH) 2 in tridentate (N, N, O) fashion. X-ray structures of [(OL2-NH)Pd(PPh3)], 2b, and [(OL1-NH)Ru(CO)(PPh3)(2)], 3a, were determined to confirm the molecular structures. The cyclic voltammograms of [(OL-NH) Ru(CO)(PPh3)(2)] exhibited two quasi reversible oxidative response near 0.25 and 1.12 V vs. SCE. The nature of HOMO as obtained by DFT calculations has been inspected to have an insight into the redox orbitals. The newly synthesized [(OL-NH) Pd(PPh3)], 2a, complexes exhibited catalytic activity toward the Suzuki, Heck, Cyanation and amination reactions. Catalytic activity of complex [(OL1-NH) Ru(CO)(PPh3)(2)], 3a, was examined for the conversion of ketones to corresponding alcohols by transfer hydrogen reactions. (C) 2015 Elsevier B.V. All rights reserved.