88200-50-4Relevant academic research and scientific papers
Synthesis, characterization, and reversible photochemical/thermal interconversion of η1- And η2-bridged (aryldiazo)triosmium clusters. Crystal structure of (μ-H)Os3(CO)10(μ-η2-N=NPh)
Samkoff, Deborah E.,Shapley, John R.,Churchill, Melvyn Rowen,Wasserman, Harvey J.
, p. 397 - 402 (2008/10/08)
H2Os3(CO)10 reacts with ArN2+BF4- (Ar = Ph, p-C6H4F4, p-C6H4CH3) in refluxing dichloromethane to produce, after neutralization, the compounds HOs3(CO)10(N2Ar) (1), in which the aryldiazo ligand bridges one edge of the osmium triangle through one nitrogen atom. UV photolyses of 1 produce the isomeric series of compounds 2, in which the aryldiazo ligand bridges one edge of the osmium triangle through both nitrogen atoms. This isomerization is reversible thermally. Quantum yields for the photoisomerization at 313 and 366 nm, 0.06 and 0.006, respectively, indicate that higher energy light is more efficient at causing the transformation. The structure of (μ-H)Os3(CO)10(μ-η1-N=N-P-C 6H4CH3) has been previously determined by a single-crystal X-ray diffraction study. The results of a crystallographic study on (μ-H)Os3(CO)10(μ-η2-N=Ph) are reported herein. This complex crystallizes in the noncentrosymmetric orthorhombic space group P212121 with a = 9.482 (2) A?, b = 12.542 (3) A?, c = 17.588 (4) A?, V= 2091.6 (7) A?3, and Z = 4. The structure was solved by a combination of Patterson, difference-Fourier, and full-matrix least-squares refinement. All non-hydrogen atoms were located; final discrepancy indices are RF = 7.7% and RwF = 7.4% for all 2114 independent data. The (μ-η2-N=NPh) ligand spans the Os(2)-Os(3) linkage, with Os(3)-N(1) RF 2.14 (2) A?, Os(2)-N(2) = 2.11 (3) A?, and N(1)-N(2) = 1.20 (4) A?. The μ-hydrido, μ-aryldiazo) dibridged Os(2)-Os(3) distance is 2.895 (2) A? as compared to Os(1)-Os(2) = 2.868 (2) A? and Os(1)-Os(3) = 2.862 (2) A?.
