Photochemistry of Transition Metal Hydride Complexes

Photo-Induced Reaction of Cp*Ru(μ-H)4RuCp* with Arenes Resulting in Irreversible Formation of μ-η2:η2-Cyclohexadiene Complexes

“…CD 2 Cl 2 was dried over MS-3A under an atmosphere of argon. [Cp*Ru(μ-H) 4 RuCp*] (1) was prepared according to the published method. 57 Other reagents were used as received.…”

“…Irradiation with visible light (436 nm) resulted in intramolecular borylene transfer, forming a μ 3 -η 3 -BC 2 ring, whereas irradiation at 313 nm induced H 2 elimination to yield a perpendicularly coordinated alkyne complex. 18 We studied the photochemical reactions of dinuclear tetrahydride-bridged complexes of ruthenium [CpsRu(μ-H) 4 RuCps] [Cps = C 5 Me 5 (Cp*) (1), C 5 Me 4 Et (Cp Et ), and C 5 H 2 t Bu 3 (Cp ‡ )] with various substrates including alkanone, 24 carbon dioxide, 25 and tetrahydrofuran (THF). 26 In the reaction with alkanone, the dinuclear μ-oxa trimethylenemethane complex was exclusively formed by successive C−H bond cleavage at the αand α′-carbons of the alkanone carbonyl group.…”

“…Investigation of the reaction modes of multinuclear polyhydrido complexes with arenes would provide profound insight into the interaction between metal surfaces and arene molecules as metal clusters have been considered to be a simplified structural model of metal surfaces. 27−29 We have reported the reactions of di-and trinuclear polyhydride clusters, [Cp*Ru(μ-H) 4 RuCp*] (1) and [{Cp*Ru(μ-H)} 3 (μ 3 -H) 2 ] (3), with benzene under thermally excited conditions. 30−32 Complex 1 reacts with benzene at 70 °C to produce a dinuclear cyclohexadiene complex, [{Cp*Ru(μ-H)} 2 (μ-η 2 :η 2 -C 6 H 8 )] (2), accompanied by dinuclear skeleton fragmentation.…”

Light-Promoted Transfer of an Iridium Hydride in Alkyl Ether Cleavage

“…Transition-metal photochemistry has been a driving force behind the development of many modern photocatalytic methods for the transformation of organic substrates. − Photocatalytic transformations can be categorized on the basis of the reactivity of the photoexcited species. In photoredox methods, the excited photocatalyst undergoes single-electron transfer (SET) with a reaction partner, with the resulting singly oxidized or reduced photocatalyst being regenerated in a subsequent SET step. − Another major class of photocatalytic processes takes advantage of light-induced ligand dissociation or extrusion. − Photoexcited transition-metal complexes can also engage in two-electron bimolecular reactivity with substrates, though this class of transformations has seen very limited application to catalytic processes.…”