Reactions of Unsaturated Quinoline Triosmium Clusters [Os3(CO)9(μ3-η2-C9H5(4-R)N)(μ-H)] (R=Me or H) with Tetramethylthiourea: X-ray Structures of [Os3(CO)8(μ-η2-C9H5(4-Me)N)(η2-SC(NMe2NCH2Me)(μ-H)2] and [Os3(CO)9(μ-η2-C9H6N)(η1-SC(NMe2)2)(μ-H)]

摘要

Treatment of the electronically unsaturated 4-methylquinoline triosmium cluster $[hbox{Os}_{3}hbox{(CO)}_{9}(upmu_3hbox{-}upeta^{2}hbox{-}hbox{C}_{9}hbox{H}_{5} hbox{(4-Me)N})(upmuhbox{-H})]$ (1) with tetramethylthiourea in refluxing cyclohexane at 81°C gave $[hbox{Os}_{3}hbox{(CO)}_{8}(upmuhbox{-}upeta^{2}hbox{-C}_{9}hbox{H}_{5} hbox{(4-Me)N})(upeta^2hbox{-SC}(hbox{NMe}_2hbox{NCH}_2hbox{Me})(upmu hbox{-H})_2]$ (2) and $[hbox{Os}_{3}hbox{(CO)}_{9}(upmuhbox{-}upeta^{2}hbox{-C}_{9}hbox{H}_{5}hbox{(4-Me)N})(upeta^1hbox{-SC}(hbox{NMe}_2)_2)(upmuhbox{-H})]$ (3). In contrast, a similar reaction of the corresponding quinoline compound $[hbox{Os}_{3}hbox{(CO)}_{9}(upmu_{3}hbox{-}upeta^{2}hbox{-C}_{9}hbox{H}_{6}hbox{N})(upmuhbox{-H})]$ (4) with tetramethylthiourea afforded $[hbox{Os}_{3}hbox{(CO)}_{9}(upmuhbox{-}upeta^{2}hbox{-C}_{9}hbox{H}_{6}hbox{N})(upeta^{1}hbox{-SC(NMe}_{2})_{2})(upmuhbox{-H)}]$ (5) as the only product. Compound 2 contains a cyclometallated tetramethylthiourea ligand which is chelating at the rear osmium atom and a quinolyl ligand coordinated to the Os3 triangle via the nitrogen lone pair and the C(8) atom of the carbocyclic ring. In 3 and 5, the tetramethylthiourea ligand is coordinated at an equatorial site of the osmium atom, which is also bound to the carbon atom of the quinolyl ligand. Compounds 3 and 5 react with PPh3 at room temperature to give the previously reported phosphine substituted products $[hbox{Os}_{3}hbox{(CO)}_{9}(upmu hbox{-}upeta^{2}hbox{-C}_{9}hbox{H}_{5}hbox{(4-Me)N)(PPh}_{3})(upmuhbox{-H)}]$ (6) and $[hbox{Os}_{3}hbox{(CO}_{9}(upmu hbox{-}upeta^{2}hbox{-C}_{9}hbox{H}_{6}hbox{N)(PPh}_{3})(upmuhbox{-H)}]$ (7) by the displacement of the tetramethylthiourea ligand.