Jeffrey E. Cortopassi

The synthesis and structural characterization of Os3(CO)8[Si(OMe)3][μ-PMe2(C6H4](μ-H)2: An unusual unsaturated triosmium cluster complex

The reaction of Os3(CO)10(NCMe)[Si(OMe)3](μ-H),1, with PMe2Ph yielded the new complex Os3(CO)10(PMe2Ph)[Si(OMe)3](μ-H),2 by substitution of the MeCn ligand with the phosphine ligand. When heated to 125°C compound2 was decarbonylated and transformed into the new unsaturated cluster complex Os3(CO)8[μ-PMe2(C6H4)][Si(OMe)3](μ-H)2,3 in 54% yield. Compound3 was characterized by a single crystal X-ray diffraction analysis, osmium bonds. The phenyl ring of the phosphine ligand has undergoneortho-metallation by a neighboring metal atom. A terminally coordinated Si(OMe)3 ligand is coordinated to the third osmium atom. The cluster is unsaturated by the amount of 2 electrons, and there is an open coordination site on the siloxyl substituted osmium atom that is partially filled by a weak interaction with one of the π-bonds of theortho-metalled phenyl ring. Complex3 reacts with CO at 1 atm to reform compound2 in 85% yield in 5 h at 40°C. Crystal Data: for3: space group = P21/n,a = 9.911(2) Å,b = 18.451(6) Å,c = 14.872(2) Å,β = 95.64(2)°,Z = 4, 1994 reflections,R = 0.028.

Cluster-assisted cyclooligomerization of thietane. A new route to polythioether macrocycles

Abstract The trirhenium complex Re 3 (CO) 10 [μ- SCH 2 CH 2 CH 2 ](μ-H) 3 ( 1 ) was found to produce an oligomerization of thietane at 25° C over 18 h to yield the new complex Re 3 (CO) 10 [μ-SCH 2 CH 2 CH 2 SCH 2 CH 2 -CH 2 SCH 2 CH 2 CH 2 SCH 2 CH 2 CH 2 ](μ-H) 3 ( 2 ), in 47% yield. Details of the structure of compound 2 were obtained rom a single crystal X-ray diffraction analysis of its PMe 2 Ph derivative 3 . It was found to contain a bridging thiolate group SCH 2 CH 2 CH 2 that is terminated with a SCH 2 CH 2 CH 2 SCH 2 CH 2 CH 2 SCH 2 CH 2 CH 2 macrocycle. The macrocycle was cleaved from the cluster by treatment with NaOEt and the free molecule trithiacyclodecane was isolated in 32% yield. Crystal data for 3 : space group = P 2 1 / n , a = 8.637(2) A, b = 41.80(1) A, c = 15.418(2) A, β = 111.79 (2)°, Z = 4, 2836 reflections, R = 0.036.

Cluster synthesis 44. The synthesis and structural characterization of an unusual new high nuclearity platinum-osmium cluster complex, Pt5Os6(CO)25

The reaction of Pt2Os4(CO)18 (1) with H2 in refluxing octane (125°C) yielded the new compound Pt5Os6(CO)25 (2), 58%. Compound 2 was characterized by IR, elemental and single crystal X-ray diffraction analyses. Compound 2 contains 11 metal atoms. five platinum, and six osmium. The cluster can be viewed as two fused trigonal bipyramidal clusters that share one platinum vertex. These two clusters are also joined by three metal-metal bonds, and Os(CO)4 groups bridge two of these three metal-metal bonds. Crystal data for 2·CH2Cl2: space group itP1¯ma=12.250(1) Å,b=17.476(4) Å,c=11.89(2) Å,α=109.87(1)°,β=112.66(1)°,γ=83.05(2)°,Z=2, 2986 reflections,R=0.033.