1,4,7-trithiacyclononane ([9]aneS(3)) and 2,5,8-trithia[9]orthocyclophane complexes of molybdenum(II) and tungsten(II): Crystal structures of [WI(CO)(3)([9]aneS(3))][BPh(4)] and [WI2(CO)(3)(NCMe)(PPh(3))]

Reaction of [MI(2)(CO)(3)(NCMe)(2)] (M = Mo or W) with a slight excess of 1,4,7-trithiacyclononane ([9]aneS(3)) in CH2Cl2 at room temperature gave the cationic complexes [MI(CO)(3)([9]aneS(3))]I 1 and 2 in high yield. Treatment of 1 and 2 with an excess of Na[BPh(4)] in methanol gave [MI(CO)(3)([9]aneS(3))][BPh(4)] 3 and 4. The molecular structure of [WI(CO)(3)([9]aneS(3))][BPh(4)] 4 has been determined by X-ray crystallography. It shows that the geometry around the tungsten centre is distorted capped octahedral with a capping carbonyl ligand. Room-temperature C-13 NMR studies on complexes 1 and 2 indicate a unique CO ligand, demonstrating that their structures in solution are similar to that found for 4 in the solid state. Reaction of [MI(2)(CO)(3)(NCMe)L] [M = Mo or W, L = PPh(3); M = W, L = P(OPh)(3)] with an equimolar quantity of [9]aneS(3) gave the seven-co-ordinate cation/anion complexes [MI(CO)(2)L([9]aneS(3))][MI(3)(CO)(4)] 5-7. Treatment of [MI(2)(CO)(3)(NCMe)(2)] with 1 equivalent of 2,5,8-trithia[9]orthocyclophane (ttoc) in CH2Cl2 at room temperature gave the dicarbonylmolybdenum complex [MoI2(CO)(2)(ttoc)] 8 or the seven-co-ordinate cation/anion tungsten complex [WI(CO)(3)(ttoc)][WI3(CO)(4)] 9. Reaction of [MI(2)(CO)(3)(NCMe)L] with an equimolar amount of ttoc gave [MI(CO)(2)L(ttoc)][MI(3)(CO)(4)] 10-12. The complex [WI2(CO)(3)(NCMe)(PPh(3))] was also shown to have a distorted capped-octahedral geometry by X-ray crystallography.