title: Facile insertion of carbon dioxide into Cu₂(μ-H) dinuclear units supported by tetraphosphine ligands.
abstract: Reactions of meso-bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm) with Cu(I) species in the presence of NaBH4 afforded di- and tetranuclear copper hydride complexes, [Cu2(μ-H)(μ-dpmppm)2]X (1) and [Cu4(μ-H)2(μ4-H)(μ-dpmppm)2]X (2) (X=BF4, PF6). Complex 1 undergoes facile insertion of CO2 (1 atm) at room temperature, leading to a formate-bridged dicopper complex [Cu2(μ-HCOO)(dpmppm)2]X (3). The experimental and DFT theoretical studies clearly demonstrate that CO2 insertion into the Cu2(μ-H) unit occurred with the flexible dicopper platform. Complex 2 also undergoes CO2 insertion to give a formate-bridged complex, [Cu4(μ-HCOO)3(dpmppm)2]X, during which the square Cu4 framework opened up to a linear tetranuclear chain.
authors.affiliation: Department of Chemistry, Faculty of Science, Nara Women's University, Kitauoya-nishi-machi, Nara, 630-8506 (Japan), Fax: (+81) 742-20-3847.
authors.forename: Kanako
authors.initials: K
authors.lastname: Nakamae
authors.forename: Bunsho
authors.initials: B
authors.lastname: Kure
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakajima
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ura
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Tanase
keywords: CO2 insertion; copper hydride complex; dinuclear complex; formate complex; tetraphosphine ligand