Opening of Carborane Cages by Metal Cluster Complexes: The Reaction of a Thiolate-Substituted Carborane with Triosmium Carbonyl Cluster Complexes

摘要

The reaction of Os-3(CO)(10)(NCMe)(2) with doso-o-(1-SCH3)-C2B10H11 has yielded the complex Os-3(CO)(9)[mu(3)-eta(3)-C2B10H9(SCH3)](mu-H)(2), 1, by the loss of the two NCMe ligands and one CO ligand from the Os-3 cluster and the coordination of the sulfur atom and the activation of two B-H bonds with transfer of the hydrogen atoms to the cluster. Reaction of 1 with a second equivalent of Os-3(CO)(10)(NCMe)(2) yielded the complex Os-3(CO)(9)(mu-H)[(mu(3)-eta(3)-1,4,5-mu(3)-eta(3)-6,10,11-C2B10H8S(CH3)]Os-3(CO)(9)(mu-H)(2),2, that contains two triosmium triangles attached to the same carborane cage. The carborane cage was opened by cleavage of two B-C bonds and one B-B bond. The B H group that was pulled out of the cage became a triply bridging group on one of the Os-3 triangles but remains bonded to the cage by two B-B bonds. When heated to 150 degrees C, 2 was transformed/ into the complex Os-3(CO)(9)(mu-H)[(mu(3)-eta(3)-mu(3)-eta(3)-C2B10H7S(CH3)]Os-3(CO)(9)(mu-H), 3, by the loss of two hydrogen atoms and a rearrangement that led to further opening of the carborane cage. Reaction of 1 with a second equivalent of closo-o-(1-SCH3)C2B10H11 has yielded the complex Os-3(CO)(6)[(mu(3)-eta(3)-C2B10H9-R-SCH3) mu(3)-eta(3)-C2B10H10-R-SCH3) (mu-H)3, 4a, containing two carborane cages coordinated to one Os-3 cluster. Compound 4a was isomerized to,the compound Os-3(CO)(6)(mu(3)-eta(3)-C2B10H9-R-SCH3)(mu(3)-eta(3)-C2B10H10-R-SCH3) (mu-H)(3), 4b, by an inversion of stereochemistry at one, of the sulfur atoms by heating to 174 degrees C.