Synthesis, structure, FAB mass spectrum, and magnetic property of a dodecanuclear cluster complex of chromium with hydrido ligands [Cr12S16(H)(2)(PEt1)(10)]

A dodecanuclear cluster complex of chromium [Cr12S16(H)(2)(PEt3)(10)] eras prepared by the reaction of a hexanuclear cluster complex [Cr6S8(H)(PEt3)(6 )] with elemental sulfur, and characterized by the FAB mass spectroscopy an d single-crystal X-ray structure analysis. Crystallographic data: [Cr12S16( H)(2)(PEt3)(10)]. 2CH(2)Cl(2) (207 K), triclinic, P (1) over bar, a = 14.69 7(6) Angstrom, b = 14.733(5) Angstrom, c = 14.238(5) Angstrom, alpha = 96.6 0(3)degrees, beta = 109.77(3)degrees, gamma = 65.69(3)degrees, Z = 1. This complex contains two octahedral Cr6S8 cluster cores linked by a Cr-Cr and t wo Cr-S bonds, and each core holds an interstitial hydrogen atom. The inter cluster bonding mode is similar to those in the superconducting Chevrel-Ser gent phases. The paramagnetic moment of the dodecanuclear cluster decreases remarkably at lower temperatures showing the antiferromagnetic coupling be tween the paramagnetic cluster centers.