title: Bimetallic ruthenium PNP pincer complex as a platform to model proposed intermediates in dinitrogen reduction to ammonia.
abstract: A series of ruthenium complexes was isolated and characterized in the course of reactions aimed at studying the reduction of hydrazine to ammonia in bimetallic systems. The diruthenium complex {[HPNPRu(N(2))](2)(μ-Cl)(2)}(BF(4))(2) (2) (HPNP = HN(CH(2)CH(2)P(i)Pr(2))(2)) reacted with 1 equiv of hydrazine to generate [(HPNPRu)(2)(μ(2)-H(2)NNH(2))(μ-Cl)(2)](BF(4))(2) (3) and with an excess of the reagent to form [HPNPRu(NH(3))(κ(2)-N(2)H(4))](BF(4))Cl (5). When phenylhydrazine was added to 2, the diazene species [(HPNPRu)(2)(μ(2)-HNNPh)(μ-Cl)(2)](BF(4))(2) (4) was obtained. Treatment of 2 with H(2) or CO yielded {[HPNPRu(H(2))](2)(μ-Cl)(2)}(BF(4))(2) (7) and [HPNPRuCl(CO)(2)]BF(4) (8), respectively. Abstraction of chloride using AgOSO(2)CF(3) or AgBPh(4) afforded the species [(HPNPRu)(2)(μ(2)-OSO(2)CF(3))(μ-Cl)(2)]OSO(2)CF(3) (9) and [(HPNPRu)(2)(μ-Cl)(3)]BPh(4) (10), respectively. Complex 3 reacted with HCl/H(2)O or HCl/Et(2)O to produce ammonia stoichiometrically; the complex catalytically disproportionates hydrazine to generate ammonia.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Sergio S
authors.initials: SS
authors.lastname: Rozenel
authors.forename: John
authors.initials: J
authors.lastname: Arnold
mesh_terms: D000641:Ammonia / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D000641:Ammonia; D012428:Ruthenium; D009584:Nitrogen