PREPARATION, CHARACTERIZATION AND ELECTROCHEMICAL STUDIES OF 1,1'-BIS(DIPHENYLPHOSPHINO)FERROCENE (DPPF) DERIVATIVES - CRYSTAL-STRUCTURE OF[DPPFCO(NO)(2)][SBF6]

The neutral dppfFe(NO)(2) (1), the novel cationic [dppfCo(NO)(2)][SbF6 ] (2), as well as the dppfFe(CO)(3) (3) (dppf = 1,1'-bis(diphenylphosp hino)ferrocene) complexes were prepared and characterized. The interac tion between the two metallic centers through the dppf ligand was stud ied in the solid state by Fe-57 Mossbauer spectroscopy and in solution by cyclic voltammetry. The Mossbauer parameters are compared with tho se of other dppfML(n) complexes. Electrochemical studies performed on these complexes show the great influence of the MLn moiety on the redo x processes of the dppf iron center. The crystal structure of complex 2 was determined (C34H28CoF6FeN2O2P2Sb). The compound crystallizes in the triclinic, space group <P(1)over bar>, a = 10.441 (2), b = 10.755( 2), c = 17.320(5) Angstrom, alpha = 104.10(2), beta = 0.504(10), gamma = 111.504(10)degrees, U = 1744.7(7) Angstrom(3), Z = 2, R = 0.0765, w R2 = 0.1878. In this complex, the cobalt atom is coordinated to two ni trosyl ligands and to phosphorus atoms of the dppf ligand, providing a distorted tetrahedral geometry. (C) 1997 Elsevier Science S.A.