Synthesis and structural characterization of ruthenium(II) complexes bearing phosphine-pyrazolyl based tripod ligands
摘要:
Phosphine-pyrazolyl based tripod ligands ROCH2C(CH(2)Pz)(2)(CH2PPh2) ( R = H, Me, allyl; Pz = pyrazol-1-yl) were e. ciently synthesized and characterized. Reactions of these ligands with [Ru(eta(6)-p-cymene)Cl-2](2) afforded complexes of the type [Ru(eta(6)-p-cymene) Cl-2](L) (6-8) in which the ligands exhibit kappa(1)-P-coordination to the metal center. Complex [Ru(eta(6)-p-cymene)Cl-2{Ph2PCH2C( CH2OH)(CH(2)Pz)(2)}] (6) underwent chloride-dissociation in CH2Cl2/MeCN to give complex [RuCl(eta(6)-p-cymene){kappa(2)(P,N)-Ph2PCH2C( CH2OH)(CH(2)Pz)(2)}][Cl] (9). Complexes 6-9 demonstrated poor to moderate catalytic activity in the transfer hydrogenation of acetophenone. All these complexes were fully characterized by analytical and spectroscopic methods and their molecular structures were determined by X-ray crystallographic study. (C) 2007 Elsevier B.V. All rights reserved.