X-ray and conformation analysis of the new trinuclear cluster of osmoim Os3(Ој,О·2-OCC6H5)(О·3-C3H5)(CO)9
V. A. Maksakov, N. V. P??rvukhina, N. V. Podberezskaya, M. Y. Afonin, V. A. Potemkin, V. P. Kirin
Keywords: triosmium carbonyl clusters, synthesis, crystal structure, conformation analysis
Pages: 926-932
Abstract
The crystal structure of the Os3(μ,η2-O=CC6H5)(η3-C3H5)(CO)9 cluster synthesized by the reaction of the (μ-H)Os3(μ-O=CC6H5)(CO)10 complex with allylamine in chloroform was determined by X-ray analysis. Prolonged storage of the reaction mixture led to N-C bond cleavage in allylamine and η3-addition of the allyl fragment at one of the Os atoms (Os-C 2.246 Е, 2.248 Е, and 2.273 Е). The unit cell parameters of the complex are a = 9.494(1) Е, b = 10.479(1) Е, c = 12.474(2) Е, α = 84.55(1)°, β = 70.08(1)°, γ =
70.72(1)°, V = 1255.8(4) Е3, space group Z = 2; C19H10O10Os3; dcalc = 2.922 g/cm3, 3085 Ihkl > 2σI of 3611 collected reflections; R = 0.0252. The structure of Os3(μ,η2-O=CC6H5)(η3-C3H5)(CO)9 is molecular. The plane of the Os3 triangle and the OsCOOs plane are connected according to the "butterfly" principle with an angle of 103.4° between them. The Os-Os distances in the cluster core vary from 2.836(1) Е to 2.844(1) Е; the Os-Ccarb distances are 1.88(1)-1.97(1) Е; the distances to the atoms of the bridging ligands are Os-C 2.11(1), Os-O 2.14(1) Е; the O-C bridging bond is 1.24(1) Е. The conformations of the Os3(μ,η2-O=CC6H5)(η3-C3H5)(CO)9 triosmium cluster were studied theoretically. The potential curve of the internal rotation of the allyl ligand relative to the Os(1)-С(9) bond was determined. The rotation barrier of the allyl ligand in crystal relative to the Os(1)-С(9) bond is 8.38 kJ/mol, and the rotation of the ligand is not hindered. The effects of the intra- and intermolecular interactions on the conformation state of the cluster complex is considered.
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