99595-18-3Relevant academic research and scientific papers
Cluster syntheses. 12. Metal-metal exchange reactions. Systematics of the synthesis of platinum-osmium carbonyl clusters containing quadruply bridging sulfido ligands
Adams, Richard D.,Babin, James E.,Mathab, Rahina,Wang, Suning
, p. 1623 - 1631 (2008/10/08)
The reaction of Os5(CO)15(μ4-S) (1) heptahydrate, Pt(PPh3)2C2H4 has yielded several new platinum-osmium clusters containing quadruply bridging sulfido ligands and Os5(CO)14(PPh3)(μ4-S) (3). The three platinum-osmium clusters PtOs4(CO)13(PPh3)(μ4-S) (2), PtOs5(CO)15(PPh3)(μ4-S) (4), and PtOs5(CO)15(PPh3)2(μ 4-S) (6) have been characterized by single-crystal X-ray diffraction analyses. For 2: space group P1, a = 13.116 (4) A?, b = 9.655 (3) A?, c = 14.669 (4) A?, α = 89.68 (3)°, β = 104.79 (2)°, γ = 89.11 (3)°, Z = 2, ρcalcd = 2.99 g/cm3. The structure was solved by the heavy-atom method and refined (4505 reflections) to the final residuals RF = 0.044 and RwF = 0.052. The molecule consists of a square-pyramidal cluster of four osmium atoms and one platinum atom with a quadruply bridging sulfido ligand on the square base. The platinum atom lies in the square base. For 4: space group P21/c, a = 8.986 (7) A?, b = 16.605 (5) A?, c = 26.005 (8) A?, β = 97.62 (4)°, Z = 4, ρcalcd = 3.21 g/cm3. The structure of 4 was solved by direct methods and was refined (3947 reflections) to the final residuals RF = 0.040 and ground = 0.048. The molecule consists of a square-pyramidal cluster of five osmium atoms with a quadruply bridging sulfido ligand on the square base and a Pt(CO)PPh3 moiety bridging one of the triosmium triangles. For 6: space group P1, a = 12.538 (2) A?, b = 15.908 (2) A?, c = 18.061 (2) A?, α = 63.008 (9)°, β = 76.629 (9)°, γ = 65.68 (1)°, Z = 2, ρcalcd = 2.45 g/cm3. The structure was solved by the heavy-atom method and was refined (4976 reflections) to the final residuals RF = 0.049 and RwF = 0.065. The molecule consists of a square-pyramidal cluster of four osmium atoms and one platinum atom with the base bridged by a quadruply bridging sulfido ligand and one of the osmium-osmium bonds in the square base bridged by an Os(CO)3(PPh3) moiety. Compound 6 is believed to be an intermediate in the formation of 2. 6 reacts with carbon monoxide to yield both 2 and 3. The yield of 6 is increased when the reaction is performed in the presence of PPh3. The yield of 4 is increased when the reaction is performed under CO. A scheme based on hexanuclear intermediates is proposed to explain the formation of all the products.
