title: Powerful Bis-facially Pyrazolate-Bridged Dinuclear Ruthenium Epoxidation Catalyst.
abstract: A new bis-facial dinuclear ruthenium complex, {[Ru(II)(bpy)]2(μ-bimp)(μ-Cl)}(2+), 2(2+), containing a hexadentate pyrazolate-bridging ligand (Hbimp) and bpy as auxiliary ligands has been synthesized and fully characterized in solution by spectrometric, spectroscopic, and electrochemical techniques. The new compound has been tested with regard to its capacity to oxidize water and alkenes. The in situ generated bis-aqua complex, {[Ru(II)(bpy)(H2O)]2(μ-bimp)}(3+), 3(3+), is an excellent catalyst for the epoxidation of a wide range of alkenes. High turnover numbers (TN), up to 1900, and turnover frequencies (TOF), up to 73 min(-1), are achieved using PhIO as oxidant. Moreover, 3(3+) presents an outstanding stereospecificity for both cis and trans olefins toward the formation of their corresponding epoxides due to specific interactions transmitted by its ligand scaffold. A mechanistic analysis of the epoxidation process has been performed based on density functional theory (DFT) calculations in order to better understand the putative cooperative effects within this dinuclear catalyst.
authors.affiliation: †Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.|‡Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Aguiló
authors.affiliation: ‡Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona, Spain.
authors.forename: Laia
authors.initials: L
authors.lastname: Francàs
authors.affiliation: †Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
authors.forename: Roger
authors.initials: R
authors.lastname: Bofill
authors.affiliation: †Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
authors.forename: Marcos
authors.initials: M
authors.lastname: Gil-Sepulcre
authors.affiliation: †Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: García-Antón
authors.affiliation: ∥Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Poater
authors.affiliation: †Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.|‡Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Llobet
authors.affiliation: †Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Escriche
authors.affiliation: ⊥Institut für Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077 Göttingen, Germany.
authors.forename: Franc
authors.initials: F
authors.lastname: Meyer
authors.affiliation: †Departament de Química, Facultat de Ciències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Sala