Seven-coordinate bromocarbonyl complexes of molybdenum (II) and tungsten(II) containing neutral sulfur donor ligands : Crystal structure of [WBr2(CO)3{PhS(CH2)2SPh-S,S′}]

Article abstract of DOI:10.1016/S0277-5387(97)00423-3

Treatment of [MBr₂(CO)₃(NCMe)₂] (M = Mo or W) with a slight excess of RS(CH₂)₂SR (R = Ph, C₆H₄F-4) in CH₂Cl₂ at room temperature gave the acetonitrile displaced products [MBr₂(CO)₃{RS(CH₂)₂SR-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 capped face, and one sulfur and two bromines in the uncapped face. Reaction of [WBr₂(CO)₃(NCMe)₂] with two equivalents of RS(CH₂)₂SR in CH₂Cl₂ at room temperature gives the cationic complexes [WBr(CO)₃{RS(CH₂)₂SR-S}{RS(CH₂) ₂SR-S,S′}]Br. Similarly, treatment of [WBr₂(CO)₃(NCMe)₂] with one and two equivalents of Ph₂P(S)CH₂P(S)Ph₂ in CH₂Cl₂ at room temperature afforded [WBr₂(CO)₃{Ph₂P(S) CH₂P(S)Ph₂-S,S′}] and [WBr(CO)₃{Ph₂P(S)CH₂P(S)Ph₂-S} {Ph₂P(S)CH₂P(S)Ph₂-S,S′}]Br respectively. Reaction of [MBr₂(CO)₃(NCMe)₂] with one equivalent of MeS(CH₂)₂S(CH₂)₂SMe in CH₂Cl₂ at room temperature gave [MoBr₂(CO)₂{MeS(CH₂)₂S(CH ₂)₂SMe-S,S′,S″}] and [WBr₂(CO)₃{MeS(CH₂)₂S(CH ₂)₂SMe-S,S′}] respectively. Finally, reaction of equimolar quantities of [MoBr₂(CO)₂(NCMe)₂] and ttob (ttob = 2,5,8-trithia[9]-o-benzenophane) gives the S₃ bonded complex [MoBr₂(CO)₂(ttob-S,S′,S″)].