| Abstract
| - The reactivity of the imine−vinylidene compounds OsCl2(CCHPh)(NHCR2)(PiPr3)2 [CR2 = CMe2, toward amines, nBuLi, and HBF4 has been studied. As a result, the formation and characterization of complexes I−IV is reported.
- The reactivity of the imine−vinylidene compounds OsCl2(CCHPh)(NHCR2)(PiPr3)2[CR2 = CMe2 (1), (2)] toward amines, nBuLi, and HBF4 has been studied.Complexes 1 and 2 react with triethylamine and diallylamine to give equilibrium mixturesof the corresponding starting materials and the five-coordinate azavinylidene derivativesOsCl(NCR2)(CCHPh)(PiPr3)2 [CR2 = CMe2 (3), (4)], which are obtainedas pure microcrystalline solids by reaction of 1 and 2 with nBuLi. The structure of 3 in thesolid state has been determined by an X-ray diffraction study. The geometry around themetal center could be described as a distorted trigonal bipyramid with apical phophinesand inequivalent angles within the Y-shaped equatorial plane. The azavinylidene groupcoordinates in a bent fashion with an Os−N−C angle of 157.2(6)°. Complexes 1 and 2 alsoreact with allylamine and aniline. The reactions initially give 3 and 4. However, the amountof these compounds decreases by increasing the reaction time. This decrease is accompaniedwith the formation of mixed amine−phosphine compounds OsCl2(CCHPh)(NHCR2)(NH2R‘)(PiPr3) [R‘ = allyl; CR2 = CMe2 (5), (6). R‘ = Ph; CR2 = CMe2 (7), (8)]. The structure of 5 in the solid state has been also determined by an X-raydiffraction study. In this case, the geometry around the osmium atom can be rationalizedas a distorted octahedron with the amine and phosphine ligands mutually trans disposedand the chlorine ligands mutually cis disposed. The X-ray analysis also shows that the NH-hydrogen atoms of the amine and the chlorines are involved in intra- and intermolecularH···Cl hydrogen bonding. The reactions of 1 and 2 with HBF4·OEt2 afford the carbynederivatives [OsCl2(⋮CCH2Ph)(NHCR2)(PiPr3)2][BF4] [CR2 = CMe2 (9), (10)].Both 1 and 2 lose the imine ligand to give OsCl2(CCHPh)(PiPr3)2 (11) in toluene underreflux.
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