Syntheses, structures and magnetic properties of new chalcogen-bridged heterodimetallic cluster compounds with heterocubane structure

The reaction of nickel, iron and cobalt complexes With MCl5 (M = Nb, Ta) and silylated chalcogen compounds in the presence of phosphane ligands yield the cluster compounds [Nb2Ni2S4Cl4(PPh3)(2)(CH3CN)(2)] (1), [Nb2Ni2Se4Cl4(PPh3)(2)(CH3CN)(2)] (2), [Ta2Ni2S4Br4(PPh3)(2)(CH3CN)(2)] (3), [Ta2Ni2Se4Br4(PPh3)(2)(CH3CN)(2)] (4), [N3S2(PMe3)(6)][Ta3NiS4(PMe3)(4)-Cl-6](2) (5), [Fe(dpPM)(2)(CH3CN)(2)][NbFe3S4Cl3(dppm)(CH3CN)](2) (6) [dppm = (diphenylphosphanyl)methane], [Fe(dpPM)(2)(CH3CN)(2)][TaFe3S4Cl3(dppm)(CH3CN)](2) (7), [FeCl(dppmSe)(2)][TaFe3Se4Cl3(dppm)(CH3CN)] (8) and [NbCo3-Se-4(PPh3)(3)(CH3CN)(3)][COCl3(PPh3)] (9). The compounds (Et4N)(3)[NbFe2S4(SPh)(4)] (10) and (Et4N)(3)[NbFe2Se4(SPh)(4)] (11) were obtained by treating (Et4N)(2)[Fe(SPh)(4)] with Li3NbE4 (E = S, Se). (Et4N)(3)[Nb2Fe6S8(SPh)(9)] (12) was synthesized by adding FeCl2 to compound 10 used as starting material. (Et4N)(3)[Nb2Fe6Se8(SePh)(9)] (13) (which is isostructural to 12) was synthesized by treating FeCl2 with NaSetBu, NbCl5 and PhSeSiMe3. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).