ALKYNE COMPLEXES OF MOLYBDENUM(II) AND TUNGSTEN(II) CONTAINING ACYCLIC AND CYCLIC THIOETHER LIGANDS - CRYSTAL-STRUCTURES OF O)-(MES(CH2)(2)S(CH2)(2)SME-S,S')(ETA(2)-PHC2PH)], [MOI(CO)([9]ANES(3)-S,S',S'')(ETA(2)-PHC2PH)]I AND [WI(TTOC-S,S',S'')(ETA(2)-PHC2PH)(2)]I-3 (TTOC = 2,5,8-TRITHIA[9]ORTHOCYCLOPHANE)

Reaction of equimolar quantities of [MX2(CO)(NCMe)(eta(2)-RC2R)(2)] an d MeS(CH2)(2)S(CH2)(2)SMe (ttn) in CH2Cl2 at room temperature gave the complexes [MI(CO)(ttn-S,S',S '')(eta(2)-RC2R)]I . Et2O (M = Mo, X = I , R = Me 1 or Ph 3; M = W, X = I, R = Me 2; M = W, X = Pr R = Ph 4), a s the only isolated products, whereas treatment of equimolar amounts o f [WI2(CO)(NCMe)(eta(2)-PhC2Ph)(2)] with ttn initially gave the crysta llographically characterised complex [WI2(CO)(ttn-S,S')(eta(2)-PhC2Ph) ] 5, which after reflux in CH2Cl2 afforded [WI(CO)(ttn-S,S',S '')(eta( 2)-PhC2Ph)]I 6. The crystal structure of 5 showed that the ttn ligand is attached to the tungsten by two adjacent sulfur atoms, leaving the third unco-ordinated. Equimolar quantities of 5 and [FeI(CO)(2)(eta-C5 H5)] gave the bimetallic complex [WI2(CO){MeS(CH2)(2)S(CH2)(2)SMe-S, S ',S '')(eta(2)-PhC2Ph){Fe(CO)(2)(eta-C5H5)]I 7. Reaction of equimolar quantities of [MoI2(CO)(NCMe)(eta(2)-PhC2Ph)(2)] and Ph2P(S)CH2P(S)Ph- 2 yielded the neutral complex [MoI2(CO){Ph2P(S)CH2P(S)Ph-2-S, S'}(eta( 2)-PhC2Ph)] 8. Treatment of equimolar amounts of [MoI2(CO)(NCMe)(eta(2 )-RC2R)(2)] with 1,4,7-trithiacyclononane ([9]aneS(3)) gave [MoI(CO)([ 9]aneS(3)-S, S', S '')(eta(2)-RC2R)(2)]I (R = Me 9 or Ph 10). Complex 10 was crystallographically characterised and shows a molybdenum atom bonded to the three sulfurs of [9]aneS(3). Its geometry is best consid ered as a distorted octahedron with the diphenylacetylene occupying on e site. Reaction of [MX2(CO)(NCMe)(eta(2)-RC2R)(2)] with an equimolar amount of 2,5,8-trithia[9]orthocyclophane (ttoc) afforded the salt com plexes [MX(CO)(ttoc-S, S', S '')(eta(2)-RC2R)]X 11-15 (M = Mo or W; X = I, R = Me or Ph; M = W, X = Pr R = Ph). The complex [WI(CO)(ttoc-S, S', S '')(eta(2)-PhC2Ph)]I 14 was transformed in CH2Cl2 in the presenc e of PhC2Ph to give the crystallographically characterised [WI(ttoc-S, S', S '')(eta(2)-PhC2Ph)(2)]I-3 16 in very low yield. The structure i s best considered as a distorted octahedron with the diphenylacetylene s each occupying one site. The shortest W-S bond is for the unique sul fur atom of ttoc trans to iodide.