STRUCTURAL DIVERSITY OF TETRANUCLEAR TUNGSTEN SULFIDE CLUSTERS - SYNTHESES AND CRYSTAL-STRUCTURES OF CLUSTERS CONTAINING RAFT-TYPE W-4(MU(3)-S)(2)(MU-S)(4) AND TETRAHEDRAL W-4(MU-S)(6) CORES

Reaction of cis-[W(N-2)(2)(PMe2Ph)(4)] 1 with 2 equivalents of (Me3Si) (2)S in the presence of an excess of MeOH gave a tetranuclear tungsten sulfide cluster [W-4(mu(3)-S)(2)(mu-S)(4)(SH)(2)(PMe2Ph)(6)] 2. Subst itution of chloride anions for the terminal SH ligands in 2 took place on reaction with 1 equivalent of SnCl2, giving the isostructural W-4 cluster [W-4(mu(3)-S)(2)(mu-S)(4)Cl-2(PMe2Ph)(6)] 3. Both 2 and 3 with ten skeletal electrons consist of an almost equilateral raft-type W-4 framework with five metal-metal bonds. On treatment with 2.4-3 equiva lents of AgOSO2CF3, compound 3 underwent two-electron oxidation to giv e 4(mu(3)-S)(2)(mu-S)(4)Cl-2(PMe2Ph)(6)][OSO2CF3](2) 4, which has a-di storted raft-type W-4 core owing to the presence of only eight skeleta l electrons. On the other hand, reduction of 3 with an excess of Na/Hg resulted in formation of the twelve-skeletal-electron cluster [W-4(mu -S)(6)(PMe2Ph)(4)] 5 containing a tetrahedral W-4 core with six W-W bo nds. The detailed structures of 2-5 were determined by single-crystal X-ray diffraction.