Unsaturated Triosmium Carbonyl Cluster Complexes with Bridging Aryl Ligands: Structures, Bonding, and Transformations

Photolysis-driven bond activation by thorium and uranium tetraosmate polyhydride complexes

Transition metal multimetallic complexes have seen intense study due to their unique bonding and potential for cooperative reactivity, but actinide-transition metal (An-TM) species are far less understood. We have synthesized uranium- and thorium-osmium heterometallic polyhydride complexes in order to study An-Os bonding and investigate the reactivity of An-Os interactions. Computational studies suggest the presence of a significant bonding interaction between the actinide center and the four coordinated osmium centers supported by bridging hydrides. Upon photolysis, these complexes undergo intramolecular C-H activation with the formation of an Os-Os bond, while the thorium complex may activate an additional C-H bond of the benzene solvent, resulting in a μ-η1,η1 phenyl ligand across one Th-Os interaction.

Multiple aromatic C-H bond activations by a dirhenium carbonyl complex

Multiple aromatic CH activations by a dirhenium complex have provided meta-related dimetallated arene rings in the complexes Re2(CO)8(μ-H)(μ-η2-1,2-μ-η2-3,4-C14H8)Re2(CO)8(μ-H), 3 and Re2(CO)8(μ-H)(μ-η1-1,μ-η1-3-C6H4)Re2(CO)8(μ-H), 4. Both products were characterized structurally by single crystal X-ray diffraction and DFT molecular orbital analyses.

Synthesis and Reactivity of Electronically Unsaturated Dirhenium Carbonyl Compounds Containing Bridging Gold-Carbene Groups

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 selective removal of the bridging Au(NHC) group. All new compounds were characterized by single-crystal X-ray diffraction analyses.

Copper-incorporated mono- and di-TeRu5 metal carbonyl complexes: syntheses, structures, and an unusual skeletal arrangement

Two sandwich-type Cu3Cl- or Cu2{Te2Ru4(CO)10}-bridging di-TeRu5 clusters, [{TeRu5(CO)14}2Cu3Cl](2-) () and [{TeRu5(CO)14}2Cu2{Te2Ru4(CO)10}](4-) (), were obtained from the reaction of [TeRu5(CO)14](2-) with 1 equiv. of [Cu(MeCN)4][BF4] in CH2Cl2 or THF at 0 °C, respectively, depending on the solvents. The chloride-abstracted was structurally characterized to have two TeRu5 cores that were linked by a Cu3Cl moiety with two Cu-Cu bonds. If the reaction was carried out in a molar ratio of 1 : 2 at 0 or 30 °C in CH2Cl2, the structural isomers [TeRu5(μ-CO)2(CO)12(CuMeCN)2] () and [TeRu5(μ-CO)3(CO)11Cu2(MeCN)2] () were produced, respectively, as the major product. Cluster displayed a TeRu5 core with two adjacent Ru3 triangles each capped by a μ3-Cu(MeCN) fragment, while contained a TeRu5 core with one triangle Ru3 plane capped by a Cu2(MeCN)2 fragment with two Cu atoms covalently bonded. Upon heating, the isomerization of into proceeded to undergo an unusual skeletal arrangement of Cu(MeCN) and migration of CO, with the TeRu5 core remaining intact. An electrochemical study revealed that and each exhibited only one oxidation while cluster had two consecutive oxidations, suggesting significant electronic communication between the two TeRu5 metal cores in via the Cu3 moiety. This work describes the facile synthesis of a series of semiconducting Cux-bridging Te-Ru carbonyl clusters, in which the incorporation of the Cux fragments has significantly influenced their resulting structures, rearrangements, and electronic properties, which was further elucidated by DFT calculations.