Isolation and structural characterisation of products from the reaction of [Os-4(mu-H)(4)(CO)(10)(MeCN)(2)] with cyclohexa-1,3-diene

The activated tetraosmium hydrido cluster, [Os-4(mu-H)(4)(CO)(10)(MeCN)(2)] 1, reacts with cyclohexa-1,3-diene producing a range of tetraosmium derivatives including the known clusters [Os-4(mu-H)(3)(CO)(11)(mu-eta(1) : eta(2)-C6H9)] 2, [Os-4(mu-H)(2)(CO)(12)(eta(2)-C6H8)], [Os-4(mu-H)(2)(CO)(11)(eta(4)-C6H8)], [Os-4(mu-H)(2)(CO)(10)(eta(6)-C6H6)] and [Os-4(CO)(9)(eta(4)-C6H8)(eta(6)-C6H6)], and the new complexes [Os-4(mu-H)(CO)(10)(mu(3)-eta(1) : eta(2) : eta(1)-C6H8)(eta(3)-C6H9)] 3, [Os-4(mu-H)(2)(CO)(10)(eta(6)-C6H5C6H9)] 4 and [Os-5(mu-H)(2)(CO)(13)(eta(4)-C6H8)] 5. The molecule structure of clusters 3,4 and 5 has been determined by single-crystal X-ray diffraction analysis, and an extensive H-1 NMR study of the cyclohexyne-allyl cluster, 3, has been described. The conversation of the cyclohexenyl cluster, [Os-4(mu-H)(3)(CO)(11)(mu-eta(1) : eta(2)-C6H9)] 2, into the new cyclohexyne complex, [Os-4(mu-H)(2)(CO)(11)(mu(3)-eta(1) : eta(2) : eta(1)-C6H8)] 6, by loss of dihydrogen is also described.