Coordination chemistry of organometallic polydentate ligands Studies on the syntheses and properties of FeM binuclear complexes prepared from organometallic tridentate ligand trans-Fe(CO) 3(Ph 2Ppy) 2 (Ph 2Ppy = 2-(diphenylphosphino)pyridine)

Abstract

The binuclear complexes (CO) 3Fe( μ-Ph 2Ppy) 2MX n (Ph 2Ppy = 2-(diphenylphosphino)pyridine, MX n = Mn(SCN) 2, Co(SCN) 2, CoCl 2, NiCl 2, Mo(CO) 3, Zn(SCN) 2, ZnCl 2, Cd(SCN) 2, CdCl 2, HgCl 2, HgI 2, AgClO 4, and SnCl 2) were prepared from the new type of organometallic tridentate ligand, trans-Fe(CO) 3(Ph 2Ppy) 2 ( 1), which contains both a basic metal center and bridging phosphine ligands. The crystal structure of the benzene solvate of 1 was determined by X-ray diffraction. The compound 1·1/2C 6H 6 crystallizes in the monoclinic space group P2 1/ c with a = 17.560(5), b = 12.110(1), c = 18.176(4) A ̊ ; β = 101.27(2)° and Z = 4 . The structure was refined to a conventional R value of 0.077 by using 2670 significant reflections and parameters. The structure of one of the binuclear complexes, namely, (CO) 3Fe(μ-Ph 2Ppy) 2HgI 2 ( 14), has also been determined by X-ray diffraction. The compound 14 crystallizes in the monoclinic space group P2 1/ n, with a = 13.829(2), b = 14.175(2), c = 19.514(3) A ̊ , β = 120.27(1)°, V = 3738(2) A ̊ 3 and Z = 4 . The structure was refined to a conventional R values of 0.032 by using 3279 significant reflections and parameters. The FeHg distance is 2.678 Å, indicative of a metal-metal bond. Results of Mössbauer and electron-absorption spectra suggested the presence of metal to metal interactions in these binuclear complexes.