Synthesis, structure, and reactivity of ruthenium(II) complexes with a hemilabile tetradentate etherdiphosphine ligand

In refluxing toluene the tetradentate ligand (Ph2PCH2CH2OCH2-)(2) (1) react s with Cl2Ru(PPh3)(3) to give the stable eta(4)-(O,O,P,P)-chelated rutheniu m(II) complex trans-Cl2Ru(Ph2PCH2CH2OCH2-)(2) (2). With carbon monoxide no transformation to an eta(3)-(O,P,P)- or eta(2)-(P,P)-chelated complex accom panied by an uptake of CO takes place. However, if [Cl2Ru(CO)(2)](n), is tr eated with 1 in a mixture of dichloromethane and 2-methoxyethanol, the eta( 3)-(O,P,P)-coordinated ruthenium(TT) complex trans-Cl2Rn(CO)(Ph2PCH2CH2OCH2 -)(2) (3) is formed. Attempts to eliminate carbon monoxide from complex 3 t o give 2 failed. Also, 3 does not react with further carbon monoxide to for m an eta(2)-(P,P)-chelated dicarbonylruthenium(II) complex. Complexes 2 and 3 have been characterized by X-ray structural analyses. (C) 2000 Elsevier Science S.A. All rights reserved.