SYNTHESES AND SPECTROSCOPIC PROPERTIES OF COMPLEXES WITH THE CUBANE-LIKE CORE (MOCU(3)SE(3)X) (X=CL, BR, I) - CRYSTAL-STRUCTURE OF [(MOCU3SE3CL)(PPH(3))(3)SE]

Mo-Cu-Se complexes with cubane-like cores {MoCu(3)Se(3)X}, [{MoCu(3)Se (3)X}(PPh(3))(3)Se] (X = Cl, Br, I) have been synthesized from CuX, Mo Se42- and PPh(3) in appropriate conditions and characterized by IR, P- 31 NMR, Mo-95 NMR and UV-vis electronic spectra. The structure of [{Mo Cu3Se3Cl}(PPh(3))(3)Se] has been determined by X-ray single crystal di ffraction analysis. The structure contains a strongly distorted cubane -like {MoCu3Se3Cl} core. Each Cu centre is bonded tetrahedrally to one P, one Cl and two Se atoms and the Mo centre is bonded tetrahedrally to four Se atoms. The mean Mo-Cu distance is 2.749(5) Angstrom. The Mo -95 NMR spectra of the title compounds along with [Ph(4)P]2MoSe4 consi st of one single resonance in the range of delta = 1303-3145 ppm. (C) 1997 Elsevier Science Ltd.