Alkyne complexes of molybdenum(II) and tungsten(II) containing acyclic and cyclic thioether ligands; crystal structures of [WI2(CO)- {MeS(CH2)2S(CH2)2SMe-S,S
′
}(η2-PhC2Ph)], [MoI(CO)([9]aneS3-S,S
′,S
″
)(η2-PhC2Ph)]I and [WI(ttoc-S,S
′,S
″
)(η2-PhC2Ph)2]I3 (ttoc = 2,5,8-trithia[9]orthocyclophane)
Abstract
Reaction of equimolar quantities of [MX2(CO)(NCMe)(η2-RC2R)2] and MeS(CH2)2S(CH2)2SMe (ttn) in CH2Cl2 at room temperature gave the complexes [MI(CO)(ttn-S,S′,S
″
)(η2-RC2R)]I·Et2O (M = Mo, X = I, R = Me 1 or Ph 3; M = W, X = I, R = Me 2; M = W, X = Br, R = Ph 4), as the only isolated products, whereas treatment of equimolar amounts of [WI2(CO)(NCMe)(η2-PhC2Ph)2] with ttn initially gave the crystallographically characterised complex [WI2(CO)(ttn-S,S
′
)(η2-PhC2Ph)] 5, which after reflux in CH2Cl2 afforded [WI(CO)(ttn-S,S
′,S
″
)(η2-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(η-C5H5)] gave the bimetallic complex [WI2(CO){MeS(CH2)2S(CH2)2SMe-S,S
′,S
″
}(η2-PhC2Ph){Fe(CO)2(η-C5H5)}]I 7. Reaction of equimolar quantities of [MoI2(CO)(NCMe)(η2-PhC2Ph)2] and Ph2P(S)CH2P(S)Ph2 yielded the neutral complex [MoI2(CO){Ph2P(S)CH2P(S)Ph2-S,S
′
}(η2-PhC2Ph)] 8. Treatment of equimolar amounts of [MoI2(CO)(NCMe)(η2-RC2R)2] with 1,4,7-trithiacyclononane ([9]aneS3) gave [MoI(CO)([9]aneS3-S,S
′,S
″
)(η2-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]aneS3. Its geometry is best considered as a distorted octahedron with the diphenylacetylene occupying one site. Reaction of [MX2(CO)(NCMe)(η2-RC2R)2] with an equimolar amount of 2,5,8-trithia[9]orthocyclophane (ttoc) afforded the salt complexes [MX(CO)(ttoc-S,S
′,S
″
)(η2-RC2R)]X 11–15 (M = Mo or W; X = I, R = Me or Ph; M = W, X = Br, R = Ph). The complex [WI(CO)(ttoc-S,S
′,S
″
)(η2-PhC2Ph)]I 14 was transformed in CH2Cl2 in the presence of PhC2Ph to give the crystallographically characterised [WI(ttoc-S,S
′,S
″
)(η2-PhC2Ph)2]I3 16 in very low yield. The structure is best considered as a distorted octahedron with the diphenylacetylenes each occupying one site. The shortest W–S bond is for the unique sulfur atom of ttoc trans to iodide.