Статья

Fast O<sub>2</sub>Binding at Dicopper Complexes Containing Schiff-Base Dinucleating Ligands

Anna CompanyDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisLaura GómezDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisRubén Mas‐BallestéDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisIvan V. KorendovychDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisXavi RibasDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisAlbert PoaterDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisTeodor ParellaDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisXavier FontrodonaDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisJordi Benet‐BuchholzDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisMiquel SolàDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisLawrence QueDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisE.V. Rybak-AkimovaDepartament de Química and Institut de Química Computacional, Universitat de Girona, Campus de Montilivi E-17071, Girona, Spain, Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA, Department of Chemistry, Tufts University, Medford, Massachusetts 02155, Servei de RMN, Universitat Autònoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain, Institute of Chemical Research of Catalonia (ICIQ) E-43007 Tarragona, Spain, and ServeisMiguel CostasUniversitat de Girona

2007en

ABI

Аннотация

A new family of dicopper(I) complexes [CuI2RL](X)2 (R=H, 1X, R=tBu, 2X and R=NO2, 3X, X=CF3SO3, ClO4, SbF6, or BArF, BArF=[B{3,5-(CF3)2C6H3}4]-), where RL is a Schiff-base ligand containing two tridentate binding sites linked by a xylyl spacer, has been prepared and characterized, and its reaction with O2 has been studied. The complexes were designed with the aim of reproducing structural aspects of the active site of type 3 dicopper proteins; they contain two three-coordinate copper sites and a rather flexible podand ligand backbone. The solid-state structures of 1ClO4, 2CF3SO3, 2ClO4, and 3BArF.CH3CN have been established by single-crystal X-ray diffraction analysis. 1ClO4 adopts a polymeric structure in the solid state while 2CF3SO3, 2ClO4, and 3BArF.CH3CN are monomeric. The complexes have been studied in solution by means of 1H and 19F NMR spectroscopy, which put forward the presence of dynamic processes. 1-3BArF and 1-3CF3SO3 in acetone react rapidly with O2 to generate metaestable [CuIII2(mu-O)2(RL)]2+ 1-3(O2) and [CuIII2(mu-O)2(CF3SO3)(RL)]+ 1-3(O2)(CF3SO3) species, respectively, that have been characterized by UV-vis spectroscopy and resonance Raman analysis. Instead, reaction of 1-3BArF with O2 in CH2Cl2 results in intermolecular O2 binding. DFT methods have been used to study the chemical identities and structural parameters of the O2 adducts, and the relative stability of the CuIII2(mu-O)2 form with respect to the CuII2(mu-eta2:eta2-O2) isomer. The reaction of 1X, X = CF3SO3 and BArF, with O2 in acetone has been studied by stopped-flow UV-vis exhibiting an unexpected very fast reaction rate (k=3.82(4)x10(3) M-1 s-1, DeltaH=4.9+/-0.5 kJ.mol-1, DeltaS=-148+/-5 J.K-1.mol-1), nearly 3 orders of magnitude faster than in the parent [CuI2(m-XYLMeAN)]2+. Thermal decomposition of 1-3(O2) does not result in aromatic hydroxylation. The mechanism and kinetics of O2 binding to 1X (X=CF3SO3 and BArF) are discussed and compared with those associated with selected examples of reported models of O2-processing copper proteins. A synergistic role of the copper ions in O2 binding and activation is clearly established from this analysis.

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Идентификаторы

DOI: 10.1021/ic0701108

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