Showing papers by "Richard D. Adams published in 2016"
TL;DR: The reaction of Os3 (CO)10 (NCMe)2 with closo-o-C2 B10 H10 has yielded two interconvertible isomers that contains two triosmium triangles attached to the same carborane cage.
Abstract: The reaction of Os3 (CO)10 (NCMe)2 with closo-o-C2 B10 H10 has yielded two interconvertible isomers Os3 (CO)9 (μ3 -4,5,9-C2 B10 H8 )(μ-H)2 (1 a) and Os3 (CO)9 (μ3 -3,4,8-C2 B10 H8 )(μ-H)2 (1 b) formed by the loss of the two NCMe ligands and one CO ligand from the Os3 cluster. Two BH bonds of the o-C2 B10 H10 were activated in its addition to the osmium cluster. A second triosmium cluster was added to the 1 a/1 b mixture to yield the complex Os3 (CO)9 (μ-H)2 (μ3 -4,5,9-μ3 -7,11,12-C2 B10 H7 )Os3 (CO)9 (μ-H)3 (2) that contains two triosmium triangles attached to the same carborane cage. When heated, 2 was transformed to the complex Os3 (CO)9 (μ-H)(μ3 -3,4,8-μ3 -7,11,12-C2 B10 H8 )Os3 (CO)9 (μ-H) (3) by a novel opening of the carborane cage with loss of H2 .
42 citations
TL;DR: The electronically unsaturated dirhenium complex has been found to exhibit aromatic C-H activation upon reaction with N,N-diethylaniline, naphthalene, and even [D6]benzene to yield the compounds in good yields.
Abstract: The electronically unsaturated dirhenium complex [Re2(CO)8(μ-H)(μ-Ph)] (1) has been found to exhibit aromatic C-H activation upon reaction with N,N-diethylaniline, naphthalene, and even [D6]benzene to yield the compounds [Re2(CO)8(μ-H)(μ-η(1)-NEt2C6H4)] (2), [Re2(CO)8(μ-H)(μ-η(2)-1,2-C10H7)] (3), and [D6]-1, respectively, in good yields. The mechanism has been elucidated by using DFT computational analyses, and involves a binuclear C-H bond-activation process.
29 citations
TL;DR: All new compounds were characterized by single-crystal X-ray diffraction analyses and the stereochemistry of the insertion was found to proceed preferentially with a cis- (syn-) stereochemistry.
Abstract: The electronically unsaturated compounds Re2(CO)8[μ-Au(NHC)](μ-Ph), 1, and Re2(CO)8[μ-Au(NHC)]2, 2, were obtained from the reaction of Re2(CO)8[μ–η2-C(H)═C(H)Bun](μ-H) with MeAu(NHC), NHC = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene. Compound 1 was converted to the new compound Re2(CO)8[μ-Au(NHC)](μ-H), 3, by reaction with H2. Addition of CO to 3 yielded the new compound Re2(CO)9[Au(NHC)](μ-H), 4, which contains a terminally coordinated Au(NHC) group on one of the rhenium atoms, and the hydrido ligand was shifted to bridge the Re–Au bond. The mechanism of the formation of 4 was established by DFT computational analyses. Compound 3 also reacted with C2H2 by an addition with insertion into the Re–H bonds to yield the compound Re2(CO)8[μ-Au(NHC)](μ-C2H3), 5, which contains a σ–π coordinated, bridging C2H3 ligand. The stereochemistry of the insertion was found to proceed preferentially with a cis- (syn-) stereochemistry. Compound 1 reacted with HCl to yield Re2(CO)8[μ-Ph](μ-H), 6, and ClAu(NHC) by selec...
11 citations
TL;DR: The reaction of Os3(CO)10(NCMe)2 with closo-o-(1-SCH3)C2B10H11 has yielded the complex Os3 (CO)9(μ-H), 3, by the loss of two hydrogen atoms and a rearrangement that led to further opening of the carborane cage.
Abstract: The reaction of Os3(CO)10(NCMe)2 with closo-o-(1-SCH3)C2B10H11 has yielded the complex Os3(CO)9[μ3-η3-C2B10H9(SCH3)](μ-H)2, 1, by the loss of the two NCMe ligands and one CO ligand from the Os3 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 Os3(CO)10(NCMe)2 yielded the complex Os3(CO)9(μ-H)[(μ3-η3-1,4,5-μ3-η3-6,10,11-C2B10H8S(CH3)]Os3(CO)9(μ-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 Os3 triangles but remains bonded to the cage by two B–B bonds. When heated to 150 °C, 2 was transformed into the complex Os3(CO)9(μ-H)[(μ3-η3-μ3-η3-C2B10H7S(CH3)]Os3(CO)9(μ-H), 3, by the loss of two hydrogen atoms and a rearrangement that led to further opening of the carborane cage. Reaction ...
10 citations
TL;DR: In this paper, the trigold compound Os5(CO)14(CH3)(μ3-AuPPh3)3, 4 was obtained from the reaction of [PPN]2[Os5-CO]15] using [Au(PPh 3]][NO3] was added to the reaction solutions.
7 citations
TL;DR: In this paper, a single-crystal X-ray diffraction analysis was performed to establish the structures of all the new products, which were established by singlecrystal diffraction analyses.
6 citations
TL;DR: In this article, the iridium-bismuth heterocyclic complex, [Ir4(CO)10(μ-BiPh2)(μ-H)]2, 1 has been obtained from the reaction of [PPN][HIr4 (CO)11] with Ph2BiCl.
4 citations
TL;DR: In this paper, the authors showed that the Os3Au(CH3) cluster provides a robust platform to study multicenter C-H bond transformations and for C-C bond formation via methyl migration/CO insertion processes.
3 citations