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Gimbert-Suriñach C, Moonshiram D, Francàs L, Planas N, Bernales V, Bozoglian F, Guda A, Mognon L, López I, Hoque MA, Gagliardi L, Cramer CJ, Llobet A. Structural and Spectroscopic Characterization of Reaction Intermediates Involved in a Dinuclear Co–Hbpp Water Oxidation Catalyst. J Am Chem Soc 2016; 138:15291-15294. [DOI: 10.1021/jacs.6b08532] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Carolina Gimbert-Suriñach
- Institute
of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain
| | - Dooshaye Moonshiram
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Laia Francàs
- Institute
of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain
| | - Nora Planas
- Department
of Chemistry, Supercomputing Institute and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Varinia Bernales
- Department
of Chemistry, Supercomputing Institute and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Fernando Bozoglian
- Institute
of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain
| | - Alexander Guda
- International
Research Center “Smart Materials”, Southern Federal University, 344090 Rostov-on-Don, Russia
| | - Lorenzo Mognon
- Institute
of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain
| | - Isidoro López
- Institute
of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain
| | - Md Asmaul Hoque
- Institute
of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain
| | - Laura Gagliardi
- Department
of Chemistry, Supercomputing Institute and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Christopher J. Cramer
- Department
of Chemistry, Supercomputing Institute and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Antoni Llobet
- Institute
of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Av. Països Catalans 16, 43007 Tarragona, Spain
- Departament
de Química, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain
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2
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Abstract
Primary copper(I)-dioxygen (O2) adducts, cupric-superoxide complexes, have been proposed intermediates in copper-containing dioxygen-activating monooxygenase and oxidase enzymes. Here, mechanisms of C-H activation by reactive copper-(di)oxygen intermediates are discussed, with an emphasis on cupric-superoxide species. Over the past 25 years, many synthetically derived cupric-superoxide model complexes have been reported. Due to the thermal instability of these intermediates, early studies focused on increasing their stability and obtaining physical characterization. More recently, in an effort to gain insight into the possible substrate oxidation step in some copper monooxygenases, several cupric-superoxide complexes have been used as surrogates to probe substrate scope and reaction mechanisms. These cupric superoxides are capable of oxidizing substrates containing weak O-H and C-H bonds. Mechanistic studies for some enzymes and model systems have supported an initial hydrogen-atom abstraction via the cupric-superoxide complex as the first step of substrate oxidation.
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Affiliation(s)
- Jeffrey J Liu
- Department of Chemistry, Johns Hopkins University, Baltimore MD 21218 (USA)
| | - Daniel E Diaz
- Department of Chemistry, Johns Hopkins University, Baltimore MD 21218 (USA)
| | - David A Quist
- Department of Chemistry, Johns Hopkins University, Baltimore MD 21218 (USA)
| | - Kenneth D Karlin
- Department of Chemistry, Johns Hopkins University, Baltimore MD 21218 (USA)
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3
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Győrffy W, Shiozaki T, Knizia G, Werner HJ. Analytical energy gradients for second-order multireference perturbation theory using density fitting. J Chem Phys 2013; 138:104104. [DOI: 10.1063/1.4793737] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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4
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Zapata-Rivera J, Caballol R, Calzado CJ. Comparing the peroxo/superoxo nature of the interaction between molecular O2 and β-diketiminato-copper and nickel complexes. Phys Chem Chem Phys 2011; 13:20241-7. [DOI: 10.1039/c1cp22121c] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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5
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Garcia-Bosch I, Company A, Frisch JR, Torrent-Sucarrat M, Cardellach M, Gamba I, Güell M, Casella L, Que L, Ribas X, Luis JM, Costas M. O2 activation and selective phenolate ortho hydroxylation by an unsymmetric dicopper mu-eta1:eta1-peroxido complex. Angew Chem Int Ed Engl 2010; 49:2406-9. [PMID: 20191646 DOI: 10.1002/anie.200906749] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Isaac Garcia-Bosch
- Departament de Química, Universitat de Girona, Campus de Montilivi, 17071 Girona, Catalonia, Spain
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6
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Ashley DC, Brinkley DW, Roth JP. Oxygen Isotope Effects as Structural and Mechanistic Probes in Inorganic Oxidation Chemistry. Inorg Chem 2010; 49:3661-75. [DOI: 10.1021/ic901778g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Daniel C. Ashley
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
| | - David W. Brinkley
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
| | - Justine P. Roth
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
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7
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Garcia-Bosch I, Company A, Frisch J, Torrent-Sucarrat M, Cardellach M, Gamba I, Güell M, Casella L, Que L, Ribas X, Luis J, Costas M. O2 Activation and Selective Phenolate ortho Hydroxylation by an Unsymmetric Dicopper μ-η1:η1-Peroxido Complex. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200906749] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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8
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de la Lande A, Salahub D, Moliner V, Gérard H, Piquemal JP, Parisel O. Dioxygen Activation by Mononuclear Copper Enzymes: Insights from a Tripodal Ligand Mimicking Their CuM Coordination Sphere. Inorg Chem 2009; 48:7003-5. [DOI: 10.1021/ic900567z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Aurélien de la Lande
- UPMC Université Paris 6 and CNRS, UMR 7616, Laboratoire de Chimie Théorique, 4 place Jussieu, 75252 Paris Cedex 05, France
- Department of Chemistry and Institute for Biocomplexity and Informatics, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Dennis Salahub
- Department of Chemistry and Institute for Biocomplexity and Informatics, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Vicent Moliner
- Departament de Química Física i Analítica, Universitat Jaume I, Box 224, SP-12080 Castelló, Spain
| | - Hélène Gérard
- UPMC Université Paris 6 and CNRS, UMR 7616, Laboratoire de Chimie Théorique, 4 place Jussieu, 75252 Paris Cedex 05, France
| | - Jean-Philip Piquemal
- UPMC Université Paris 6 and CNRS, UMR 7616, Laboratoire de Chimie Théorique, 4 place Jussieu, 75252 Paris Cedex 05, France
| | - Olivier Parisel
- UPMC Université Paris 6 and CNRS, UMR 7616, Laboratoire de Chimie Théorique, 4 place Jussieu, 75252 Paris Cedex 05, France
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9
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Smirnov VV, Lanci MP, Roth JP. Computational Modeling of Oxygen Isotope Effects on Metal-Mediated O2 Activation at Varying Temperatures. J Phys Chem A 2009; 113:1934-45. [DOI: 10.1021/jp807796c] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Valeriy V. Smirnov
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
| | - Michael P. Lanci
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
| | - Justine P. Roth
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218
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10
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Güell M, Luis JM, Siegbahn PEM, Solà M. Theoretical study of the hydroxylation of phenols mediated by an end-on bound superoxo–copper(II) complex. J Biol Inorg Chem 2008; 14:273-85. [DOI: 10.1007/s00775-008-0447-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 10/30/2008] [Indexed: 10/21/2022]
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11
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Malmqvist PA, Pierloot K, Shahi ARM, Cramer CJ, Gagliardi L. The restricted active space followed by second-order perturbation theory method: theory and application to the study of CuO2 and Cu2O2 systems. J Chem Phys 2008; 128:204109. [PMID: 18513012 DOI: 10.1063/1.2920188] [Citation(s) in RCA: 359] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A multireference second-order perturbation theory using a restricted active space self-consistent field wave function as reference (RASPT2/RASSCF) is described. This model is particularly effective for cases where a chemical system requires a balanced orbital active space that is too large to be addressed by the complete active space self-consistent field model with or without second-order perturbation theory (CASPT2 or CASSCF, respectively). Rather than permitting all possible electronic configurations of the electrons in the active space to appear in the reference wave function, certain orbitals are sequestered into two subspaces that permit a maximum number of occupations or holes, respectively, in any given configuration, thereby reducing the total number of possible configurations. Subsequent second-order perturbation theory captures additional dynamical correlation effects. Applications of the theory to the electronic structure of complexes involved in the activation of molecular oxygen by mono- and binuclear copper complexes are presented. In the mononuclear case, RASPT2 and CASPT2 provide very similar results. In the binuclear cases, however, only RASPT2 proves quantitatively useful, owing to the very large size of the necessary active space.
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Affiliation(s)
- Per Ake Malmqvist
- Department of Theoretical Chemistry, University of Lund, P.O. Box 124, S-221 00 Lund, Sweden
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12
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Cramer CJ, Gour JR, Kinal A, Włoch M, Piecuch P, Moughal Shahi AR, Gagliardi L. Stereoelectronic Effects on Molecular Geometries and State-Energy Splittings of Ligated Monocopper Dioxygen Complexes. J Phys Chem A 2008; 112:3754-67. [DOI: 10.1021/jp800627e] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher J. Cramer
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, Department of Chemistry, Ege University, 35100 Bornova/Izmir, Turkey, and Department of Physical Chemistry, Sciences II University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Jeffrey R. Gour
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, Department of Chemistry, Ege University, 35100 Bornova/Izmir, Turkey, and Department of Physical Chemistry, Sciences II University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Armagan Kinal
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, Department of Chemistry, Ege University, 35100 Bornova/Izmir, Turkey, and Department of Physical Chemistry, Sciences II University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Marta Włoch
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, Department of Chemistry, Ege University, 35100 Bornova/Izmir, Turkey, and Department of Physical Chemistry, Sciences II University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Piotr Piecuch
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, Department of Chemistry, Ege University, 35100 Bornova/Izmir, Turkey, and Department of Physical Chemistry, Sciences II University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Abdul Rehaman Moughal Shahi
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, Department of Chemistry, Ege University, 35100 Bornova/Izmir, Turkey, and Department of Physical Chemistry, Sciences II University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - Laura Gagliardi
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, Department of Chemistry and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, Department of Chemistry, Ege University, 35100 Bornova/Izmir, Turkey, and Department of Physical Chemistry, Sciences II University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
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13
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Lanci MP, Smirnov VV, Cramer CJ, Gauchenova EV, Sundermeyer J, Roth JP. Isotopic probing of molecular oxygen activation at copper(I) sites. J Am Chem Soc 2007; 129:14697-709. [PMID: 17960903 DOI: 10.1021/ja074620c] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Copper-dioxygen (CuO2) adducts are frequently proposed as intermediates in enzymes, yet their electronic and vibrational structures have not always been understood. [Cu(eta1-O2)TMG3tren]+ (TMG3tren = 1,1,1-tris{2-[N2-(1,1,3,3-tetramethylguanidino)]ethyl}amine) features end-on (eta1) O2 coordination in the solid state. Described here is an investigation of the compound's solution properties by nuclear magnetic resonance spectroscopy, density functional calculations, and oxygen isotope effects. The study yields two major findings. First, [Cu(eta1-O2)TMG3tren]+ is paramagnetic due to a triplet electronic structure; this is in contrast to other copper compounds where O2 is bound in a side-on manner. Second, the oxygen equilibrium isotope effect upon O2 binding to copper(I) (18O EIE [triple bond] K(16O16O)/K(16O18O) = 1.0148 +/- 0.0012) is significantly larger than those determined for iron and cobalt eta1-O2 adducts. This result is suggested to reflect greater ionic (CuII-O2-I) character within the valence bond description. A revised interpretation of the physical origins of the 18O EIEs upon O2 binding to redox metals is also advanced along with experimental data that should be used as benchmarks for interpreting 18O kinetic isotope effects upon enzyme reactions.
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Affiliation(s)
- Michael P Lanci
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
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14
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Gurlo A. Interplay between O2 and SnO2: oxygen ionosorption and spectroscopic evidence for adsorbed oxygen. Chemphyschem 2007; 7:2041-52. [PMID: 16955518 DOI: 10.1002/cphc.200600292] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Tin dioxide is the most commonly used material in commercial gas sensors based on semiconducting metal oxides. Despite intensive efforts, the mechanism responsible for gas-sensing effects on SnO(2) is not fully understood. The key step is the understanding of the electronic response of SnO(2) in the presence of background oxygen. For a long time, oxygen interaction with SnO(2) has been treated within the framework of the "ionosorption theory". The adsorbed oxygen species have been regarded as free oxygen ions electrostatically stabilized on the surface (with no local chemical bond formation). A contradiction, however, arises when connecting this scenario to spectroscopic findings. Despite trying for a long time, there has not been any convincing spectroscopic evidence for "ionosorbed" oxygen species. Neither superoxide ions O(2)(-), nor charged atomic oxygen O,(-) nor peroxide ions O(2)(2-) have been observed on SnO(2) under the real working conditions of sensors. Moreover, several findings show that the superoxide ion does not undergo transformations into charged atomic oxygen at the surface, and represents a dead-end form of low-temperature oxygen adsorption on reduced metal oxide.
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Affiliation(s)
- Alexander Gurlo
- Institute of Physical and Theoretical Chemistry, University of Tuebingen Auf der Morgenstelle 15, 72076 Tübingen, Germany
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15
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Cramer CJ, Tolman WB. Mononuclear Cu-O2 complexes: geometries, spectroscopic properties, electronic structures, and reactivity. Acc Chem Res 2007; 40:601-8. [PMID: 17458929 PMCID: PMC2593863 DOI: 10.1021/ar700008c] [Citation(s) in RCA: 321] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Using interwoven experimental and theoretical methods, detailed studies of several structurally defined 1:1 Cu-O 2 complexes have provided important fundamental chemical information useful for understanding the nature of intermediates involved in aerobic oxidations in synthetic and enzymatic copper-mediated catalysis. In particular, these studies have shed new light on the factors that influence the mode of O 2 coordination (end-on vs side-on) and the electronic structure, which can vary between Cu(II)-superoxo and Cu(III)-peroxo extremes.
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Affiliation(s)
- Christopher J Cramer
- Department of Chemistry, Supercomputer Institute, and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street Southeast, Minneapolis, Minnesota 55410, USA.
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16
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Roth JP. Advances in studying bioinorganic reaction mechanisms: isotopic probes of activated oxygen intermediates in metalloenzymes. Curr Opin Chem Biol 2007; 11:142-50. [PMID: 17307017 DOI: 10.1016/j.cbpa.2007.01.683] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Accepted: 01/23/2007] [Indexed: 11/18/2022]
Abstract
Metalloenzymes catalyze reactions of molecular oxygen and its reduced forms through the controlled formation of metal-bound, activated oxygen intermediates. These intermediates have been a challenge to characterize and new experimental approaches capable of relating structure to reactivity under physiologically relevant conditions are needed. The application of a competitive isotope fractionation technique has enabled changes in O-O bonding to be probed during enzyme-catalyzed reactions. The derived isotope effects provide insights into the reaction mechanisms of O2 and O2*-, which probably could not have been obtained using more conventional methods.
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Affiliation(s)
- Justine P Roth
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore MD 21218, USA.
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de la Lande A, Moliner V, Parisel O. Singlet-triplet gaps in large multireference systems: Spin-flip-driven alternatives for bioinorganic modeling. J Chem Phys 2007; 126:035102. [PMID: 17249901 DOI: 10.1063/1.2423010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The proper description of low-spin states of open-shell systems, which are commonly encountered in the field of bioinorganic chemistry, rigorously requires using multireference ab initio methodologies. Such approaches are unfortunately very CPU-time consuming as dynamic correlation effects also have to be taken into account. The broken-symmetry unrestricted (spin-polarized) density functional theory (DFT) technique has been widely employed up to now to bypass that drawback, but despite a number of relative successes in the determination of singlet-triplet gaps, this framework cannot be considered as entirely satisfactory. In this contribution, we investigate some alternative ways relying on the spin-flip time-dependent DFT approach [Y. Shao et al. J. Chem. Phys. 118, 4807 (2003)]. Taking a few well-documented copper-dioxygen adducts as examples, we show that spin-flip (SF)-DFT computed singlet-triplet gaps compare very favorably to either experimental results or large-scale CASMP2 computations. Moreover, it is shown that this approach can be used to optimize geometries at a DFT level including some multireference effects. Finally, a clear-cut added value of the SF-DFT computations is drawn: if pure ab initio data are required, then the electronic excitations revealed by SF-DFT can be considered in designing dramatically reduced zeroth-order variational spaces to be used in subsequent multireference configuration interaction or multireference perturbation treatments.
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Affiliation(s)
- Aurélien de la Lande
- Laboratoire de Chimie Théorique, UMR 7616 CNRS/UPMC, Université Pierre et Marie Curie, Paris 6, Case courrier 137- 4, place Jussieu, F. 75252 Paris Cedex 05, France
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18
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de la Lande A, Gérard H, Moliner V, Izzet G, Reinaud O, Parisel O. Theoretical modelling of tripodal CuN3 and CuN4 cuprous complexes interacting with O2, CO or CH3CN. J Biol Inorg Chem 2006; 11:593-608. [PMID: 16791643 DOI: 10.1007/s00775-006-0107-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2005] [Accepted: 04/03/2006] [Indexed: 11/29/2022]
Abstract
Dioxygen binding at copper enzymatic sites is a fundamental aspect of the catalytic activity observed in many biological systems such as the monooxygenases, especially peptidylglycine alpha-hydroxylating monooxygenase (PHM), in which two mononuclear Cu(I) sites are involved. Biomimetic models have been developed: dipods, tripods, and, more recently, functionalized calixarenes. The modelling of calixarene systems, although not unreachable for theory yet, requires, however, a number of preliminary investigations to ensure proper calibrations if relevant description of the metal-ligand interaction at the hybrid quantum mechanical/molecular mechanics levels of theory is the aim. In this paper, we report quantum chemistry investigations on a coherent series of representative cuprous tripodal species characterized by (1) monodentate ligands [Cu(ImH)3]+ (where ImH is imidazole), [Cu(MeNH2)3]+ and [Cu(MeNH2)4]+ , (2) neutral tripodal ligands [CuCH(ImH)3]+, [Cu(tren)]+ [where tren is tris(2-aminoethyl)amine], and [Cu(trenMe3)]+ [where trenMe3 is tris(2-methylaminoethyl)amine] and (3) a hydrido-tris(pyrazolyl)borate [CuBH(Pyra)3]. The structures of these complexes, the coordination mode (eta(2) side-on or eta(1) end-on) of O2 to Cu(I) and the charge transfer from the metal to dioxygen have been computed. For some systems, the coordination by CH3CN and CO is also reported. Beyond results relative to structural properties, an interesting feature is that it is possible to build from computational results only a set of abacuses linking the nu(16O-16O) vibrational frequency of the coordinated O2 molecule to the O-O bond length or to the net charge of the O2 moiety. Such abacuses may help experimentalists in distinguishing between the four possible ways of binding O2 to CuN3 and CuN4 cuprous centres, namely (1) end-on triplet states, (2) side-on triplet states, (3) end-on singlet states and (4) side-on singlet states. These abacuses are extended to three tripods obtained by the substitution of one nitrogen atom by either a phosphorus or a sulphur atom. Moreover, it is shown that any factor favouring pyramidalization at copper favours charge transfer and thus coordination of the incoming O2 moiety. All these allow insight into the coordination mode of O2 and into the charge transfer from Cu(I) in site Cu(M) of PHM.
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Affiliation(s)
- Aurélien de la Lande
- Laboratoire de Chimie Théorique, UMR 7616 CNRS, Université Pierre et Marie Curie, Paris 6, Case courrier 137-4, place Jussieu, 75252, Paris Cedex 05, France
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20
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Aboelella NW, Gherman BF, Hill LMR, York JT, Holm N, Young VG, Cramer CJ, Tolman WB. Effects of thioether substituents on the O2 reactivity of beta-diketiminate-Cu(I) complexes: probing the role of the methionine ligand in copper monooxygenases. J Am Chem Soc 2006; 128:3445-58. [PMID: 16522125 PMCID: PMC2593856 DOI: 10.1021/ja057745v] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The activation of dioxygen by dopamine beta-monooxygenase (DbetaM) and peptidylglycine alpha-hydroxylating monooxygenase (PHM) is postulated to occur at a copper site ligated by two histidine imidazoles and a methionine thioether, which is unusual because such thioether ligation is not present in other O2-activating copper proteins. To assess the possible role of the thioether ligand in O2 activation by DbetaM and PHM, two new ligands comprising beta-diketiminates with thioether substituents were synthesized and Cu(I) and Cu(II) complexes were isolated. The Cu(II) compounds are monomeric and exhibit intramolecular thioether coordination. While the Cu(I) complexes exhibit a multinuclear topology in the solid state, variable-temperature 1H NMR studies implicate equilibria in solution, possibly including monomers with intramolecular thioether coordination that are structurally defined by DFT calculations. Low-temperature oxygenation of solutions of the Cu(I) complexes generates stable 1:1 Cu/O2 adducts, which on the basis of combined experimental and theoretical studies adopt side-on "eta(2)" structures with negligible Cu-thioether bonding and significant peroxo-Cu(III) character. In contrast to previously reported findings with related ligands lacking the thioether group, however (cf., Aboelella; et al. J. Am. Chem. Soc. 2004, 126, 16896), purging the solutions of the thioether-containing adducts with argon results in conversion to bis(mu-oxo)dicopper(III) species. A role for the thioether in promoting loss of O2 from the 1:1 Cu/O2 adduct and facilitating trapping of the resulting Cu(I) complex to yield the bis(mu-oxo) species is proposed, and the possible relevance of this role to that of the methionine in the active sites of DbetaM and PHM is discussed.
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Affiliation(s)
- Nermeen W Aboelella
- Department of Chemistry, Center for Metals in Biocatalysis, and Minnesota Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA
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21
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Smirnov VV, Roth JP. Evidence for Cu−O2 Intermediates in Superoxide Oxidations by Biomimetic Copper(II) Complexes. J Am Chem Soc 2006; 128:3683-95. [PMID: 16536541 DOI: 10.1021/ja056741n] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mechanism by which [Cu(II)(L)](OTf)2 and [Cu(II)N3(L)](OTf) (L = TEPA: tris(2-pyridylethyl)amine or TMPA: tris(2-pyridylmethyl)amine; OTf = trifluoromethanesulfonate) react with superoxide (O2*-) to form [Cu(I)(L)](OTf) and O2 is described. Evidence for a CuO2 intermediate is presented based on stopped-flow experiments and competitive oxygen (18O) kinetic isotope effects on the bimolecular reactions of (16,16)O2*- and (18,16)O2*- ((16,16)k/(18,16)k). The (16,16)k/(18,16)k fall within a narrow range from 0.9836 +/- 0.0043 to 0.9886 +/- 0.0078 for reactions of copper(II) complexes with different coordination geometries and redox potentials that span a 0.67 V range. The results are inconsistent with a mechanism that involves either rate-determining O2*- binding or one-step electron transfer. Rather a mechanism involving formation of a CuO2 intermediate prior to the loss of O2 in the rate-determining step is proposed. Calculations of similar inverse isotope effects, using stretching frequencies of CuO2 adducts generated from copper(I) complexes and O2, suggest that the intermediate has a superoxo structure. The use of 18O isotope effects to relate activated oxygen intermediates in enzymes to those derived from inorganic compounds is discussed.
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Affiliation(s)
- Valeriy V Smirnov
- Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA
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22
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Hill LMR, Gherman BF, Aboelella NW, Cramer CJ, Tolman WB. Electronic tuning of β-diketiminate ligands with fluorinated substituents: effects on the O2-reactivity of mononuclear Cu(i) complexes. Dalton Trans 2006:4944-53. [PMID: 17047744 DOI: 10.1039/b609939d] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Copper(i) complexes with the beta-diketiminate ligands HC{C(R)N(Dipp)}{C(R')N(Dipp)}(-) (Dipp = C(6)H(3)(i)Pr(2-)2,6; L(1), R = CF(3), R' = CH(3); L(2), R = R' = CF(3)) have been isolated and fully characterized. On the basis of X-ray structural comparisons with the previously reported complex LCu(CH(3)CN) (L = HC{C(CH(3))N(Dipp)}(2)(-)), the ligand environments at the copper centers in the analogous nitrile adducts with L(1) and L(2) impose similar steric demands. L(1)Cu(CH(3)CN) reacts instantaneously at low temperature with O(2) to form a thermally-unstable intermediate with an isotope-sensitive vibration at 977 cm(-1) (928 cm(-1) with (18)O(2)), in accord with the peroxo O-O stretch associated with side-on coordination for LCu(O(2)). However, L(2)Cu(CH(3)CN) is unreactive toward O(2) even at room temperature. Evaluation of the redox potentials of the nitrile adducts and the CO stretching frequencies of the carbon monoxide adducts revealed an incremental adjustment of the electronic environment at the copper center that correlated with the extent of ligand fluorination. Furthermore, theoretical calculations (DFT, CASPT2) predicted that an increasing extent of Cu(ii)-superoxo character and end-on coordination of the O(2) moiety in the Cu/O(2) product (L(2) > L(1) > L) are accompanied by increases in the free energy for the oxygenation reaction, with L(2) unable to support a Cu/O(2) intermediate. Calculations also predict the 1 : 1 Cu/O(2) adducts to be unreactive with respect to hydrogen atom abstraction from hydrocarbon substrates on the basis of their stability towards both reduction and protonation.
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Affiliation(s)
- Lyndal M R Hill
- Department of Chemistry, Center for Metals in Biocatalysis, and Supercomputer Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, 55455-0431, USA
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23
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Gherman BF, Heppner DE, Tolman WB, Cramer CJ. Models for dioxygen activation by the CuB site of dopamine β-monooxygenase and peptidylglycine α-hydroxylating monooxygenase. J Biol Inorg Chem 2005; 11:197-205. [PMID: 16344970 DOI: 10.1007/s00775-005-0066-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Accepted: 11/21/2005] [Indexed: 11/30/2022]
Abstract
On the basis of spectroscopic and crystallographic data for dopamine beta-monooxygenase and peptidylglycine alpha-hydroxylating monooxygenase (PHM), a variety of ligand sets have been used to model the oxygen-binding Cu site in these enzymes. Calculations which employed a combination of density functional and multireference second-order perturbation theory methods provided insights into the optimal ligand set for supporting eta (1) superoxo coordination as seen in a crystal structure of a precatalytic Cu/O(2) complex for PHM (Prigge et al. in Science 304:864-867, 2004). Anionic ligand sets stabilized eta (2) dioxygen coordination and were found to lead to more peroxo-like Cu-O(2) complexes with relatively exergonic binding free energies, suggesting that these adducts may be unreactive towards substrates. Neutral ligand sets (including a set of two imidazoles and a thioether), on the other hand, energetically favored eta (1) dioxygen coordination and exhibited limited dioxygen reduction. Binding free energies for the 1:1 adducts with Cu supported by the neutral ligand sets were also higher than with their anionic counterparts. Deviations between the geometry and energetics of the most analogous models and the PHM crystal structures suggest that the protein environment influences the coordination geometry at the Cu(B) site and increases the lability of water bound to the preoxygenated reduced form. Another implication is that a neutral ligand set will be critical in biomimetic models in order to stabilize eta (1) dioxygen coordination.
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Affiliation(s)
- Benjamin F Gherman
- Department of Chemistry and Supercomputer Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
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