title: [Fe4] and [Fe6] Hydride Clusters Supported by Phosphines: Synthesis, Characterization, and Application in N2Reduction.
abstract: Multiple iron atoms bridged by hydrides is a common structural feature of the active species that have been postulated in the biological and industrial reduction of N2. In this study, the reactions of an Fe(II) amide complex with pinacolborane in the presence/absence of phosphines afforded a series of hydride-supported [Fe4] and [Fe6] clusters Fe4(μ-H)4(μ3-H)2{N(SiMe3)2}2(PR3)4(PR3= PMe3(2a), PMe2Ph (2b), PEt3(2c)), Fe6(μ-H)10(μ3-H)2(PMe3)10(3), and (η6-C7H8)Fe4(μ-H)2{μ-N(SiMe3)2}2{N(SiMe3)2}2(4), which were characterized crystallographically and spectroscopically. Under ambient conditions, these clusters catalyzed the silylation of N2to furnish up to 160 ± 13 equiv of N(SiMe3)3per 2c (40 equiv per Fe atom) and 183 ± 18 equiv per 3 (31 equiv per Fe atom). With regard to the generation of the reactive species, dissociation of phosphine and hydride ligands from the [Fe4] and [Fe6] clusters was indicated, based on the results of the mass spectrometric analysis on the [Fe6] cluster, as well as the formation of a diphenylsilane adduct of the [Fe4] cluster.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Araake
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sakadani
authors.forename: Mizuki
authors.initials: M
authors.lastname: Tada
authors.affiliation: Department of Chemistry, Daido University , Takiharu-cho, Minami-ku, Nagoya 457-8530, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: PRESTO, Japan Science and Technology Agency (JST) , Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Yasuhiro
authors.identifier: 0000-0001-5573-2821
authors.initials: Y
authors.lastname: Ohki