16406-49-8Relevant articles and documents
Facile cycloreversion of octacarbonyl-1,2-diosmacyclobutane: Convenient source of the Os2(CO)8 unit in the formation of 1,2-diosmacyclobutenes
Burke, Michael R.,Seils, Frank,Takats, Josef
, p. 1445 - 1450 (2008/10/08)
Cycloreversion of octacarbonyl-1,2-diosmacyclobutane, Os2(CO)8(μ-η1:η1-CH 2CH2) (1), can be affected by mild thermal (T > 28°C) or photochemical (λ > 330 nm) activation. In the presence of activated alkynes the reaction affords 1,2-diosmacyclobutenes in moderate to good yields, Os2(CO)8(μ-η1:η 1-RCCR′) (R = R′ = CO2Me (2a), Ph (2b); R = H, R′ = CO2Me (2c), C(O)Me (2d)). Compounds 2 have been characterized by IR and NMR spectroscopies. The 13C NMR spectra indicate that the molecules are static at room temperature with regard to CO exchange processes. A detailed preparation of 1 is reported as well.
Metal-induced cleavage of carbon-sulfur bonds in thiolato ligands. Thermolysis of HOs3(CO)10(μ-SC6H5) under CO pressure. The synthesis and crystal and molecular structures off Os4(CO)13(μ3-S) and Os5(CO)15(μ4-S)
Adams, Richard D.,Horvàth, Istvàn T.,Segmüller, Brigitte E.,Yang, Li-Wu
, p. 1301 - 1308 (2008/10/08)
The thermolysis of HOs3(CO)10(μ-SC6H5), I, has been studied under carbon monoxide pressures of 200 and 1800 psi at 150°C. At 200 psi, I eliminates C6H6 and forms the new compounds Os4(CO)13(μ3-S), II, and Os5(CO)15(μ4-S), III, and the known compounds Os3(CO)9(μ3-S)2, IV, and Os3(CO)12. Compounds II and III have been characterized by X-ray crystallographic methods. For II: space group P1, No. 2, a = 9.608 (2) A?, b = 15.402 (2) A?, c = 15.703 (3) A?, α = 113.29 (2)°, β = 99.04 (2)°, γ = 95.52 (2)°, V = 2077 (2) A?3, Z = 4, ρcalcd = 3.70 g/cm3. The structure was solved by the heavy-atom method. For 3998 reflections (F2 ≥ 3.0σ(F2)) RF = 0.040 and RwF = 0.046. The structure consists of a butterfly cluster of four osmium atoms with a triply bridging sulfido ligand on one triangular group of three. There are 13 linear terminal carbonyl ligands. When heated in the absence of CO, II loses 1 mol of CO and forms the Os4(CO)12(μ3-S) which contains a closed tetrahedron of four metal atoms. For III: space group Pna21, No. 33, a = 19.119 (4) A?, b = 7.724 (6) A?, c = 16.417 (4) A?, V = 2424 (3) A?3, Z = 4, ρcalcd = 3.84 g/cm3. The structure was solved by direct methods. For 1520 reflections (F2 ≥ 3.0σ(F2)) RF = 0.037 and RwF = 0.042. The structure consists of a square-pyramidal cluster of five osmium atoms with a quadruply bridging sulfido ligand spanning the square base. Each metal atom contains three linear terminal carbonyl ligands. At 1800 psi of CO pressure thermolysis of I yields C6H6, Os3(CO)9(μ3-S)2, and Os(CO)5 only. A reaction mechanism involving Os3-(CO)9(μ3-S) and Os(CO)4 intermediates is proposed and discussed.
