7-COORDINATE BROMOCARBONYL COMPLEXES OF MOLYBDENUM(II) AND TUNGSTEN(II) CONTAINING NEUTRAL SULFUR DONOR LIGANDS - CRYSTAL-STRUCTURE OF [WBR2(CO)(3)(PHS(CH2)(2)SPH-S,S')]

Treatment of [MBr2(CO)(3)(NCMe)(2)] (M = Mo or W) with a slight excess of RS(CH2)(2)SR (R = Ph, C6H4F-4) in CH2Cl2 at room temperature gave the acetonitrile displaced products [MBr2(CO)(3){RS(CH2)(2)SR-S,S'}]. The complex with M = W, R = Ph was crystallographically characterised and has a distorted capped octahedral geometry with one carbonyl group in the capping position, two carbonyls and one sulfur atom in the cap ped face, and one sulfur and two bromines in the uncapped face. Reacti on of [WBr2(CO)(3)(NCMe)(2)] with two equivalents of RS(CH2)(2)SR in C H2Cl2 at room temperature gives the cationic complexes [WBr(CO)(3){RS( CH2)(2)SR-S}{RS(CH2)(2)SR-S,S'}]Br. Similarly, treatment of [WBr2(CO)( 3)(NCMe)(2)] with one and two equivalents of Ph2P(S)CH2P(S)Ph-2 in CH2 Cl2 at room temperature afforded [WBr2(CO)(3){Ph2P(S) CH2P(S)Ph-2-S,S' }] and {Ph2P(S)CH2P(S)Ph-2-S}{Ph2P(S)CH2P(S)Ph-2-S,S'}]Br respectively . Reaction of [MBr2(CO)(3)(NCMe)(2)] with one equivalent of MeS(CH2)(2 )S(CH2)(2)SMe in CH2Cl2 at room temperature gave [MoBr2(CO)(2){MeS(CH2 )(2)S(CH2)(2)SMe-S,S',S''}] and [WBr2(CO)(3){MeS(CH2)(2)S(CH2)(2)SMe-S ,S'}] respectively. Finally, reaction of equimolar quantities of [MoBr 2(CO)(2)(NCMe)(2)] and ttob (ttob = 2,5,8-trithia[9]-o-benzenophane) g ives the S-3 bonded complex [MoBr2(CO)(2)(ttob-S,S',S'')]. (C) 1998 El sevier Science Ltd. All rights reserved.