NEW EFFICIENT SYNTHESIS OF THE TRIANGULAR CLUSTER [W3SE4(H2O)(9)](4-RAY STRUCTURE OF THE FIRST MIXED-METAL SELENO-BRIDGED CUBANE-TYPE TUNGSTEN-TIN CLUSTER E2NH2)(6)[(SCN)(9)W3SE4SNCL3]CENTER-DOT-0.5H(2)O() ANDX)

The trinuclear incomplete cuboidal [W3Se4(H2O)(9)](4+) cluster has bee n prepared by reacting polymeric solid W3Se7Br4 with H3PO2 in aqueous HCl solution with yields up to 50%. The mixed-metal cluster compound ( Me2NH2)(6)[(SCN)(9)W3Se4SnCl3]. 0.5H(2)O (1) has been prepared by reac ting [W3Se4(H2O)(9)](4+) in aqueous HCl solution with SnCl2 . 2H(2)O i n the presence of Me2NH2Cl and NaSCN. Crystals of 1 are monoclinic spa ce group C2/c, a = 42.868(6), b = 12.035(1), c = 21.976(5) Angstrom, b eta = 95.69(1)degrees and Z = 8. The structure was refined by full-mat rix least-squares techniques to R(Rw) = 0.0343(0.0478), The title comp ound 1 is the first mixed-metal seleno-bridged cubane-type tungsten-ti n cluster as derivative of [W3Se4(H2O)(9)](4+). (C) 1998 Elsevier Scie nce S.A.