1
|
Karnes JP, Kumar A, Hopkins Leseberg JA, Day VW, Blakemore JD. Trivalent Cations Slow Electron Transfer to Macrocyclic Heterobimetallic Complexes. Inorg Chem 2024; 63:8710-8729. [PMID: 38669449 DOI: 10.1021/acs.inorgchem.4c00230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
Incorporation of secondary redox-inactive cations into heterobimetallic complexes is an attractive strategy for modulation of metal-centered redox chemistry, but quantification of the consequences of incorporating strongly Lewis acidic trivalent cations has received little attention. Here, a family of seven heterobimetallic complexes that pair a redox-active nickel center with La3+, Y3+, Lu3+, Sr2+, Ca2+, K+, and Na+ (in the form of their triflate salts) have been prepared on a heteroditopic ligand platform to understand how chemical behavior varies across the comprehensive series. Structural data from X-ray diffraction analysis demonstrate that the positions adopted by the secondary cations in the crown-ether-like site of the ligand relative to nickel are dependent primarily on the secondary cations' ionic radii and that the triflate counteranions are bound to the cations in all cases. Electrochemical data, in concert with electron paramagnetic resonance studies, show that nickel(II)/nickel(I) redox is modulated by the secondary metals; the heterogeneous electron-transfer rate is diminished for the derivatives incorporating trivalent metals, an effect that is dependent on steric crowding about the nickel metal center and that was quantified here with a topographical free-volume analysis. As related analyses carried out here on previously reported systems bear out similar relationships, we conclude that the placement and identity of both the secondary metal cations and their associated counteranions can afford unique changes in the (electro)chemical behavior of heterobimetallic species.
Collapse
Affiliation(s)
- Joseph P Karnes
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Amit Kumar
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Julie A Hopkins Leseberg
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W Day
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D Blakemore
- Department of Chemistry, University of Kansas, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| |
Collapse
|
2
|
Bím D, Alexandrova AN. Electrostatic regulation of blue copper sites. Chem Sci 2021; 12:11406-11413. [PMID: 34667549 PMCID: PMC8447924 DOI: 10.1039/d1sc02233d] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 07/26/2021] [Indexed: 01/06/2023] Open
Abstract
In the last 50 years, the blue copper proteins became central targets of investigation. Extensive experiments focused on the Cu coordination to probe the effect of local perturbations on its properties. We found that local electric fields, generated by charged residues evolutionarily placed throughout the protein edifice, mainly second sphere, but also more remotely, constitute an additional significant factor regulating blue copper proteins. These fields are not random, but exhibit a highly specific directionality, negative with respect to the and vectors in the Cu first shell. The field magnitude contributes to fine-tuning of the geometric and electronic properties of Cu sites in individual blue copper proteins. Specifically, the local electric fields evidently control the Cu–SMet bond distance, Cu(ii)–SCys bond covalency, and the energies of the frontier molecular orbitals, which, in turn, govern the Cu(ii/i) reduction potential and the relative absorption intensities at 450 nm and 600 nm. Intramolecular electric fields in blue copper proteins are oriented in a fixed way to modulate properties of their copper sites: they control the first-shell copper interactions to influence geometric, spectroscopic, and redox behavior.![]()
Collapse
Affiliation(s)
- Daniel Bím
- Department of Chemistry and Biochemistry, University of California, Los Angeles 607 Charles E. Young Drive East Los Angeles CA 90095-1569 USA
| | - Anastassia N Alexandrova
- Department of Chemistry and Biochemistry, University of California, Los Angeles 607 Charles E. Young Drive East Los Angeles CA 90095-1569 USA .,California NanoSystems Institute, University of California, Los Angeles 570 Westwood Plaza Los Angeles California 90095-1569 USA
| |
Collapse
|
3
|
Mishra S, Bhandari A, Singh D, Gupta R, Olmstead MM, Patra AK. Bis(μ-thiolato)-dicopper Containing Fully Spin Delocalized Mixed Valence Copper-Sulfur Clusters and Their Electronic Structural Properties with Relevance to the Cu A Site. Inorg Chem 2021; 60:5779-5790. [PMID: 33829770 DOI: 10.1021/acs.inorgchem.1c00075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
With aromatic and aliphatic thiol-S donor Schiff base ligands, the copper-sulfur clusters, [(L1)8CuI6CuII2](ClO4)2·DMF·0.5CH3OH (1) and [(L2)12CuI5CuII11(μ4-S)(μ4-O)6](ClO4)·4H2O, respectively, have been reported ( Chem. Commun. 2017, 53, 3334); HL1/HL2 are 2-(((3-methylthiophen-2-yl)methylene)amino)benzene/ethanethiol). Complex 1 comprises a wheel shaped Cu8S8 framework, made up of interlinked Cu2{μ-S(R)}2 units. To understand the properties with relevance to the CuA site and to check whether self-assembly generates similar type clusters to 1, three complexes, [(L3)8CuI6CuII2](ClO4)2·(C2H5)2O·2.5H2O (2), [(L3Cl)8CuI6CuII2](ClO4)2·1.25(C2H5)2O·1.25CH3OH·2H2O (3), and [(L3CF3)8CuI6CuII2](ClO4)2·2(C2H5)2O·H2O (4) have been synthesized with supporting ligands HL3X (HL3 = 2-((furan-2-ylmethylene)amino)benzenethiol when X = -H; X = -Cl or -CF3 para to thiol-S are HL3Cl and HL3CF3 ligands, respectively). The X-ray structures of 3 and 4 feature a similar Cu8S8 architecture to 1. The spectroscopic properties and the X-ray structures revealed that 2-4 are fully spin delocalized mixed valence (MV) of class-III type clusters. The structural parameters of the N2Cu2{μ-S(R)}2 units of 3 and 4 closely resemble those of the MV binuclear CuA site. With the aid of UV-vis-NIR, EPR, and spectroelectrochemical studies, the electronic properties of these complexes have been described in comparison with the MV model complexes and CuA site.
Collapse
Affiliation(s)
- Saikat Mishra
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713 209, India
| | - Anirban Bhandari
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713 209, India
| | - Devender Singh
- Department of Chemistry, University of Delhi, Delhi 110 007, India
| | - Rajeev Gupta
- Department of Chemistry, University of Delhi, Delhi 110 007, India
| | - Marilyn M Olmstead
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Apurba K Patra
- Department of Chemistry, National Institute of Technology Durgapur, Mahatma Gandhi Avenue, Durgapur 713 209, India
| |
Collapse
|
4
|
Spectroelectrochemical studies of structural changes during reduction of oxygen catalyzed by laccase adsorbed on modified carbon nanotubes. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.113820] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Schrempp DF, Leingang S, Schnurr M, Kaifer E, Wadepohl H, Himmel HJ. Inter- and Intramolecular Electron Transfer in Copper Complexes: Electronic Entatic State with Redox-Active Guanidine Ligands. Chemistry 2017; 23:13607-13611. [PMID: 28771843 DOI: 10.1002/chem.201703611] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Indexed: 02/01/2023]
Abstract
Fast and efficient electron transfer in blue copper proteins is realized by a structural harmonization between the CuI and CuII complex pair ("entatic state" model). Herein, we present now a CuI /CuII complex pair with redox-active guanidine ligands showing almost perfect match between both redox states. By modifying the ligand electron donor strength, the redox chemistry of the copper complex can be controlled to be either metal-centered or to cross the borderline to ligand-centered. This work is the first systematic study of complexes with redox-active ligands within the concept of the entatic state.
Collapse
Affiliation(s)
- David F Schrempp
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Simone Leingang
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Martin Schnurr
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Elisabeth Kaifer
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120, Heidelberg, Germany
| |
Collapse
|
6
|
Witte M, Rohrmüller M, Gerstmann U, Henkel G, Schmidt WG, Herres-Pawlis S. [Cu 6 (NGuaS) 6 ] 2+ and its oxidized and reduced derivatives: Confining electrons on a torus. J Comput Chem 2017; 38:1752-1761. [PMID: 28394037 DOI: 10.1002/jcc.24798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 02/04/2017] [Accepted: 03/11/2017] [Indexed: 12/14/2022]
Abstract
The hexanuclear thioguanidine mixed-valent copper complex cation [Cu6 (NGuaS)6 ]+2 (NGuaS = o-SC6 H4 NC(NMe2 )2 ) and its oxidized/reduced states are theoretically analyzed by means of density functional theory (DFT) (TPSSh + D3BJ/def2-TZV (p)). A detailed bonding analysis using overlap populations is performed. We find that a delocalized Cu-based ring orbital serves as an acceptor for donated S p electrons. The formed fully delocalized orbitals give rise to a confined electron cloud within the Cu6 S6 cage which becomes larger on reduction. The resulting strong electrostatic repulsion might prevent the fully reduced state. Experimental UV/Vis spectra are explained using time-dependent density functional theory (TD-DFT) and analyzed with a natural transition orbital analysis. The spectra are dominated by MLCTs within the Cu6 S6 core over a wide range but LMCTs are also found. The experimental redshift of the reduced low energy absorption band can be explained by the clustering of the frontier orbitals. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Matthias Witte
- Lehrstuhl für Bioanorganische Chemie, Fachgruppe Chemie, RWTH Aachen University, Landoltweg 1, Aachen, 52074, Germany
| | - Martin Rohrmüller
- Lehrstuhl für Theoretische Physik, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Uwe Gerstmann
- Lehrstuhl für Theoretische Physik, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Gerald Henkel
- Lehrstuhl für Anorganische Chemie, Universität Paderborn, Warburger Str.100, Paderborn, 33098, Germany
| | - Wolf Gero Schmidt
- Lehrstuhl für Theoretische Physik, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Sonja Herres-Pawlis
- Lehrstuhl für Bioanorganische Chemie, Fachgruppe Chemie, RWTH Aachen University, Landoltweg 1, Aachen, 52074, Germany
| |
Collapse
|
7
|
Hollmann K, Oppermann A, Witte M, Li S, Amen M, Flörke U, Egold H, Henkel G, Herres-Pawlis S. Copper(I) Complexes with Thiourea Derivatives as Ligands: Revealing Secrets of Their Bonding Scheme. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201601547] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Katharina Hollmann
- RWTH Aachen University; Institut für Anorganische Chemie; Landoltweg 1 52074 Aachen Germany
| | - Alexander Oppermann
- RWTH Aachen University; Institut für Anorganische Chemie; Landoltweg 1 52074 Aachen Germany
| | - Matthias Witte
- RWTH Aachen University; Institut für Anorganische Chemie; Landoltweg 1 52074 Aachen Germany
| | - Sun Li
- Universität Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - Maike Amen
- Universität Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - Ulrich Flörke
- Universität Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - Hans Egold
- Universität Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - Gerald Henkel
- Universität Paderborn; Warburger Str. 100 33098 Paderborn Germany
| | - Sonja Herres-Pawlis
- RWTH Aachen University; Institut für Anorganische Chemie; Landoltweg 1 52074 Aachen Germany
| |
Collapse
|
8
|
A personal perspective on the discovery of dioxygen adducts of copper and iron by Nobumasa Kitajima. J Biol Inorg Chem 2017; 22:237-251. [DOI: 10.1007/s00775-016-1432-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 12/15/2016] [Indexed: 11/26/2022]
|
9
|
Hurd CA, Besley NA, Robinson D. A QM/MM study of the nature of the entatic state in plastocyanin. J Comput Chem 2016; 38:1431-1437. [PMID: 27859435 PMCID: PMC5434870 DOI: 10.1002/jcc.24666] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/23/2016] [Accepted: 10/27/2016] [Indexed: 11/27/2022]
Abstract
Plastocyanin is a copper containing protein that is involved in the electron transfer process in photosynthetic organisms. The active site of plastocyanin is described as an entatic state whereby its structure represents a compromise between the structures favored by the oxidized and reduced forms. In this study, the nature of the entatic state is investigated through density functional theory‐based hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamics simulations. The strain energy is computed to be 12.8 kcal/mol and 14.5 kcal/mol for the oxidized and reduced forms of the protein, indicating that the active site has an intermediate structure. It is shown that the energy gap between the oxidized and reduced forms varies significantly with the fluctuations in the structure of the active site at room temperature. An accurate determination of the reorganization energy requires averaging over conformation and a large region of the protein around the active site to be treated at the quantum mechanical level. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Catherine A Hurd
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - Nicholas A Besley
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| | - David Robinson
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
| |
Collapse
|
10
|
Mann SI, Heinisch T, Weitz AC, Hendrich MP, Ward TR, Borovik AS. Modular Artificial Cupredoxins. J Am Chem Soc 2016; 138:9073-6. [PMID: 27385206 DOI: 10.1021/jacs.6b05428] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cupredoxins are electron-transfer proteins that have active sites containing a mononuclear Cu center with an unusual trigonal monopyramidal structure (Type 1 Cu). A single Cu-Scys bond is present within the trigonal plane that is responsible for its unique physical properties. We demonstrate that a cysteine-containing variant of streptavidin (Sav) can serve as a protein host to model the structure and properties of Type 1 Cu sites. A series of artificial Cu proteins are described that rely on Sav and a series of biotinylated synthetic Cu complexes. Optical and EPR measurements highlight the presence of a Cu-Scys bond, and XRD analysis provides structural evidence. We further provide evidence that changes in the linker between the biotin and Cu complex within the synthetic constructs allows for small changes in the placement of Cu centers within Sav that have dramatic effects on the structural and physical properties of the resulting artificial metalloproteins. These findings highlight the utility of the biotin-Sav technology as an approach for simulating active sites of metalloproteins.
Collapse
Affiliation(s)
- Samuel I Mann
- Department of Chemistry, University of California-Irvine , 1102 Natural Sciences II, Irvine, California 92697, United States
| | - Tillmann Heinisch
- Department of Chemistry, University of Basel , Spitalstrasse 51, CH-4056 Basel, Switzerland
| | - Andrew C Weitz
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Michael P Hendrich
- Department of Chemistry, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Thomas R Ward
- Department of Chemistry, University of Basel , Spitalstrasse 51, CH-4056 Basel, Switzerland
| | - A S Borovik
- Department of Chemistry, University of California-Irvine , 1102 Natural Sciences II, Irvine, California 92697, United States
| |
Collapse
|
11
|
Witte M, Grimm-Lebsanft B, Goos A, Binder S, Rübhausen M, Bernard M, Neuba A, Gorelsky S, Gerstmann U, Henkel G, Gero Schmidt W, Herres-Pawlis S. Optical response of the Cu2 S2 diamond core in Cu2II(NGuaS)2 Cl2. J Comput Chem 2016; 37:2181-92. [PMID: 27362786 DOI: 10.1002/jcc.24439] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/10/2016] [Accepted: 06/13/2016] [Indexed: 01/25/2023]
Abstract
Density functional theory (DFT) and time-dependent DFT calculations are presented for the dicopper thiolate complex Cu2 (NGuaS)2 Cl2 [NGuaS=2-(1,1,3,3-tetramethylguanidino) benzenethiolate] with a special focus on the bonding mechanism of the Cu2 S2 Cl2 core and the spectroscopic response. This complex is relevant for the understanding of dicopper redox centers, for example, the CuA center. Its UV/Vis absorption is theoretically studied and found to be similar to other structural CuA models. The spectrum can be roughly divided in the known regions of metal d-d absorptions and metal to ligand charge transfer regions. Nevertheless the chloride ions play an important role as electron donors, with the thiolate groups as electron acceptors. The bonding mechanism is dissected by means of charge decomposition analysis which reveals the large covalency of the Cu2 S2 diamond core mediated between Cu dz2 and S-S π and π* orbitals forming Cu-S σ bonds. Measured resonant Raman spectra are shown for 360- and 720-nm excitation wavelength and interpreted using the calculated vibrational eigenmodes and frequencies. The calculations help to rationalize the varying resonant behavior at different optical excitations. Especially the phenylene rings are only resonant for 720 nm. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Matthias Witte
- Lehrstuhl Für Bioanorganische Chemie, Fachgruppe Chemie, RWTH Aachen University, Landoltweg 1, Aachen, 52074, Germany
| | - Benjamin Grimm-Lebsanft
- Institut für Nanostruktur- und Festkörperphysik and Center for Free Electron Laser Science, University of Hamburg, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Arne Goos
- Institut für Nanostruktur- und Festkörperphysik and Center for Free Electron Laser Science, University of Hamburg, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Stephan Binder
- Institut für Nanostruktur- und Festkörperphysik and Center for Free Electron Laser Science, University of Hamburg, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Michael Rübhausen
- Institut für Nanostruktur- und Festkörperphysik and Center for Free Electron Laser Science, University of Hamburg, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Martin Bernard
- Lehrstuhl Für Anorganische Chemie, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Adam Neuba
- Lehrstuhl Für Anorganische Chemie, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Serge Gorelsky
- Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada
| | - Uwe Gerstmann
- Lehrstuhl Für Theoretische Physik, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Gerald Henkel
- Lehrstuhl Für Anorganische Chemie, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Wolf Gero Schmidt
- Lehrstuhl Für Theoretische Physik, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany
| | - Sonja Herres-Pawlis
- Lehrstuhl Für Bioanorganische Chemie, Fachgruppe Chemie, RWTH Aachen University, Landoltweg 1, Aachen, 52074, Germany
| |
Collapse
|
12
|
Esmieu C, Orio M, Le Pape L, Lebrun C, Pécaut J, Ménage S, Torelli S. Redox-Innocent Metal-Assisted Cleavage of S–S Bond in a Disulfide-Containing Ligand. Inorg Chem 2016; 55:6208-17. [DOI: 10.1021/acs.inorgchem.6b00819] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Charlène Esmieu
- CEA-BIG-LCBM-BioCE, Univ. Grenoble Alpes, CNRS UMR 5249, 17 rue des Martyrs, 38054 Grenoble, France
| | - Maylis Orio
- Institut des Sciences Moléculaires de Marseille, Aix Marseille Université, CNRS, Centrale Marseille, ISM2 UMR 7313, 13097 Marseille, France
| | - Laurent Le Pape
- CEA-BIG-LCBM-BioCE, Univ. Grenoble Alpes, CNRS UMR 5249, 17 rue des Martyrs, 38054 Grenoble, France
| | | | | | - Stéphane Ménage
- CEA-BIG-LCBM-BioCE, Univ. Grenoble Alpes, CNRS UMR 5249, 17 rue des Martyrs, 38054 Grenoble, France
| | - Stéphane Torelli
- CEA-BIG-LCBM-BioCE, Univ. Grenoble Alpes, CNRS UMR 5249, 17 rue des Martyrs, 38054 Grenoble, France
| |
Collapse
|
13
|
A motif for reversible nitric oxide interactions in metalloenzymes. Nat Chem 2016; 8:663-9. [DOI: 10.1038/nchem.2502] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 03/11/2016] [Indexed: 01/12/2023]
|
14
|
Hayes EC, Porter TR, Barrows CJ, Kaminsky W, Mayer JM, Stoll S. Electronic Structure of a Cu(II)-Alkoxide Complex Modeling Intermediates in Copper-Catalyzed Alcohol Oxidations. J Am Chem Soc 2016; 138:4132-45. [PMID: 26907976 PMCID: PMC4988936 DOI: 10.1021/jacs.5b13088] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In the copper-catalyzed oxidation of alcohols to aldehydes, a Cu(II)-alkoxide (Cu(II)-OR) intermediate is believed to modulate the αC-H bond strength of the deprotonated substrate to facilitate the oxidation. As a structural model for these intermediates, we characterized the electronic structure of the stable compound Tp(tBu)Cu(II)(OCH2CF3) (Tp(tBu) = hydro-tris(3-tert-butyl-pyrazolyl)borate) and investigated the influence of the trifluoroethoxide ligand on the electronic structure of the complex. The compound exhibits an electron paramagnetic resonance (EPR) spectrum with an unusually large gzz value of 2.44 and a small copper hyperfine coupling Azz of 40 × 10(-4) cm(-1) (120 MHz). Single-crystal electron nuclear double resonance (ENDOR) spectra show that the unpaired spin population is highly localized on the copper ion (≈68%), with no more than 15% on the ethoxide oxygen. Electronic absorption and magnetic circular dichroism (MCD) spectra show weak ligand-field transitions between 5000 and 12,000 cm(-1) and an intense ethoxide-to-copper charge transfer (LMCT) transition at 24,000 cm(-1), resulting in the red color of this complex. Resonance Raman (rR) spectroscopy reveals a Cu-O stretch mode at 592 cm(-1). Quantum chemical calculations support the interpretation and assignment of the experimental data. Compared to known Cu(II)-thiolate and Cu(II)-alkylperoxo complexes from the literature, we found an increased σ interaction in the Cu(II)-OR bond that results in the spectroscopic features. These insights lay the basis for further elucidating the mechanism of copper-catalyzed alcohol oxidations.
Collapse
Affiliation(s)
- Ellen C. Hayes
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195
| | | | - Charles J. Barrows
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195
| | - Werner Kaminsky
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195
| | | | - Stefan Stoll
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195
| |
Collapse
|
15
|
Witte M, Gerstmann U, Neuba A, Henkel G, Schmidt WG. Density functional theory of the CuA
-like Cu2
S2
diamond core in Cu
2II(NGuaS)2
Cl2. J Comput Chem 2016; 37:1005-18. [DOI: 10.1002/jcc.24289] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 11/07/2022]
Affiliation(s)
- M. Witte
- Department of Physics, Lehrstuhl Für Theoretische Materialphysik, Universität Paderborn; Paderborn 33098 Germany
| | - U. Gerstmann
- Department of Physics, Lehrstuhl Für Theoretische Materialphysik, Universität Paderborn; Paderborn 33098 Germany
| | - A. Neuba
- Department of Chemistry, Lehrstuhl Für Anorganische Chemie, Universität Paderborn; Paderborn 33098 Germany
| | - G. Henkel
- Department of Chemistry, Lehrstuhl Für Anorganische Chemie, Universität Paderborn; Paderborn 33098 Germany
| | - W. G. Schmidt
- Department of Physics, Lehrstuhl Für Theoretische Materialphysik, Universität Paderborn; Paderborn 33098 Germany
| |
Collapse
|
16
|
Wilfer C, Liebhäuser P, Hoffmann A, Erdmann H, Grossmann O, Runtsch L, Paffenholz E, Schepper R, Dick R, Bauer M, Dürr M, Ivanović-Burmazović I, Herres-Pawlis S. Efficient Biomimetic Hydroxylation Catalysis with a Bis(pyrazolyl)imidazolylmethane Copper Peroxide Complex. Chemistry 2015; 21:17639-49. [PMID: 26458073 DOI: 10.1002/chem.201501685] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Indexed: 11/08/2022]
Abstract
Bis(pyrazolyl)methane ligands are excellent components of model complexes used to investigate the activity of the enzyme tyrosinase. Combining the N donors 3-tert-butylpyrazole and 1-methylimidazole results in a ligand that is capable of stabilising a (μ-η(2) :η(2) )-dicopper(II) core that resembles the active centre of tyrosinase. UV/Vis spectroscopy shows blueshifted UV bands in comparison to other known peroxo complexes, due to donor competition from different ligand substituents. This effect was investigated with the help of theoretical calculations, including DFT and natural transition orbital analysis. The peroxo complex acts as a catalyst capable of hydroxylating a variety of phenols by using oxygen. Catalytic conversion with the non-biological phenolic substrate 8-hydroxyquinoline resulted in remarkable turnover numbers. In stoichiometric reactions, substrate-binding kinetics was observed and the intrinsic hydroxylation constant, kox , was determined for five phenolates. It was found to be the fastest hydroxylation model system determined so far, reaching almost biological activity. Furthermore, Hammett analysis proved the electrophilic character of the reaction. This sheds light on the subtle role of donor strength and its influence on hydroxylation activity.
Collapse
Affiliation(s)
- Claudia Wilfer
- Department für Chemie und Pharmazie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München (Germany).,Institut für Anorganische Chemie, Rheinisch-Westfälische Technische Hochschule Aachen, Landoltweg 1, 52074 Aachen (Germany)
| | - Patricia Liebhäuser
- Institut für Anorganische Chemie, Rheinisch-Westfälische Technische Hochschule Aachen, Landoltweg 1, 52074 Aachen (Germany)
| | - Alexander Hoffmann
- Institut für Anorganische Chemie, Rheinisch-Westfälische Technische Hochschule Aachen, Landoltweg 1, 52074 Aachen (Germany)
| | - Hannes Erdmann
- Department für Chemie und Pharmazie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München (Germany)
| | - Oleg Grossmann
- Department für Chemie und Pharmazie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München (Germany)
| | - Leander Runtsch
- Department für Chemie und Pharmazie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München (Germany)
| | - Eva Paffenholz
- Institut für Anorganische Chemie, Rheinisch-Westfälische Technische Hochschule Aachen, Landoltweg 1, 52074 Aachen (Germany)
| | - Rahel Schepper
- Department Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn (Germany)
| | - Regina Dick
- Department Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn (Germany)
| | - Matthias Bauer
- Department Chemie, Universität Paderborn, Warburger Straße 100, 33098 Paderborn (Germany)
| | - Maximilian Dürr
- Department Chemie und Pharmazie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen (Germany)
| | - Ivana Ivanović-Burmazović
- Department Chemie und Pharmazie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen (Germany)
| | - Sonja Herres-Pawlis
- Department für Chemie und Pharmazie, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München (Germany). .,Institut für Anorganische Chemie, Rheinisch-Westfälische Technische Hochschule Aachen, Landoltweg 1, 52074 Aachen (Germany).
| |
Collapse
|
17
|
Kumar R, Obrai S, Mitra J, Sharma A. DFT studies of structural and some spectral parameters of copper(II) complexes with N,N,N',N″-tetrakis (2-hydroxyethyl/propyl) ethylenediamine and tris(2-hydroxyethyl)amine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 115:244-249. [PMID: 23835057 DOI: 10.1016/j.saa.2013.06.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 05/25/2013] [Accepted: 06/04/2013] [Indexed: 06/02/2023]
Abstract
The structures and some spectral parameters of three copper(II) complexes; [Cu(THEEN)(H2O)](PIC)2 (1), [Cu(THPEN)] (PIC)2 C3H8O (2) and [Cu(TEAH3)(PIC)] (PIC)⋅(H2O) (3), previously synthesized and characterized by X-ray diffraction, are here computationally studied by using density functional theory (DFT) in its hybrid form B3LYP. In these complexes, THEEN is N,N,N',N″-tetrakis(2-hydroxyethyl) ethylenediamine and THPEN is N,N,N',N″-tetrakis(2-hydroxypropyl) ethylenediamine, tetrapodal ligands and TEAH3 is tris(2-hydroxyethyl)amine, a tripodal ligand. The primary coordination sphere of copper(II) ion in complexes (1), (2) and (3) are optimized, structural parameters are calculated, vibrational bands are assigned and energy gaps of frontier orbital (HOMO-LUMO) have been calculated with B3LYP/6-31G/LANL2DZ level of theory using DMSO as solvent. The calculated geometric and spectral results reproduced the experimental data with well agreement. Theoretical calculated molecular orbitals (HOMO-LUMO) and their energies have been calculated that suggest charge transfer occurs within the complexes.
Collapse
Affiliation(s)
- Rakesh Kumar
- Department of Chemistry, Dr. B.R. Ambedkar National Institute of Technology, Jalandhar 144 011, Punjab, India
| | | | | | | |
Collapse
|
18
|
Zhang S, Çelebi-Ölçüm N, Melzer MM, Houk KN, Warren TH. Copper(I) nitrosyls from reaction of copper(II) thiolates with S-nitrosothiols: mechanism of NO release from RSNOs at Cu. J Am Chem Soc 2013; 135:16746-9. [PMID: 24111922 DOI: 10.1021/ja406476y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
S-nitrosothiols (RSNOs) serve as ready sources of biological nitric oxide activity, especially in conjunction with copper centers. We report a novel pathway for the generation of NO within the coordination sphere of copper model complexes from reaction of copper(II) thiolates with S-nitrosothiols. Reaction of tris(pyrazolyl)borate copper(II) thiolates (iPr2)TpCu-SR (R = C6F5 or CPh3) with (t)BuSNO leads to formation of (iPr2)TpCu(NO) and the unsymmetrical disulfide RS-S(t)Bu. Quantum mechanical investigations with B3LYP-D3/6-311G(d) suggest formation of a κ(1)-N-RSNO adduct (iPr2)TpCu(SR)(R'SNO) that precedes release of RSSR' to deliver (iPr2)TpCu(NO). This process is reversible; reaction of (iPr2)TpCu(NO) (but not (iPr2)TpCu(NCMe)) with C6F5S-SC6F5 forms (iPr2)TpCu-SC6F5. Coupled with the facile, reversible reaction between (iPr2)TpCu(NO) and C6F5SNO to give (iPr2)TpCu-SC6F5 and 2 equiv NO, we outline a new, detailed catalytic cycle for NO generation from RSNOs at Cu.
Collapse
Affiliation(s)
- Shiyu Zhang
- Department of Chemistry, Georgetown University , Box 571227-1227, Washington, DC 20057, United States
| | | | | | | | | |
Collapse
|
19
|
Fujisawa K, Noguchi N, Noguchi Y, Lehnert N. [Bis(3,5-diisopropylpyrazol-1-yl-κ N2)dihydroborato](triphenylphosphane-κ P)copper(I). Acta Crystallogr C 2013; 69:943-6. [DOI: 10.1107/s0108270113015965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 06/07/2013] [Indexed: 11/10/2022] Open
Abstract
In the title compound, [Cu(C18H32BN4)(C18H15P)], the CuIion is coordinated by two N atoms from the anionic bidentate chelating bis(3,5-diisopropylpyrazol-1-yl)dihydroborate ligand [average Cu—N distance = 1.994 (3) Å] and the P atom from a triphenylphosphane ligand [Cu—P distance = 2.1676 (8) Å] in a trigonal geometry [the sum of the angles around the CuIatom is 359.6 (1)°]. The N—Cu—N angle between adjacent coordinated pyrazole-ring N atoms is 98.99 (9)°, while the average N—Cu—P angle between the coordinated pyrazole N atom and the triphenylphosphane P atom is 130.3 (1)°.
Collapse
|
20
|
Biswas S, Dutta A, Dolai M, Bhowmick I, Rouzières M, Lee HM, Clérac R, Ali M. Dinuclear Cu
II
–Cu
II
and Cu
I
–Cu
II
Complexes of a Compartmental Ligand – Syntheses, Structures, Magnetic, and Catalytic Studies. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300576] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Surajit Biswas
- Department of Chemistry, Jadavpur University, Kolkata 700 032, India E‐mail: , http://www.jaduniv.edu.in/profile.php?uid=30
| | - Arpan Dutta
- Department of Chemistry, Jadavpur University, Kolkata 700 032, India E‐mail: , http://www.jaduniv.edu.in/profile.php?uid=30
| | - Malay Dolai
- Department of Chemistry, Jadavpur University, Kolkata 700 032, India E‐mail: , http://www.jaduniv.edu.in/profile.php?uid=30
| | - Indrani Bhowmick
- CNRS, CRPP, UPR 8641, 33600 Pessac, France
- Univ. Bordeaux, CRPP, UPR 8641, 33600 Pessac, France
| | - Mathieu Rouzières
- CNRS, CRPP, UPR 8641, 33600 Pessac, France
- Univ. Bordeaux, CRPP, UPR 8641, 33600 Pessac, France
| | - Hon Man Lee
- National Changhua University of Education, Department of Chemistry, Changhua 50058, Taiwan
| | - Rodolphe Clérac
- CNRS, CRPP, UPR 8641, 33600 Pessac, France
- Univ. Bordeaux, CRPP, UPR 8641, 33600 Pessac, France
| | - Mahammad Ali
- Department of Chemistry, Jadavpur University, Kolkata 700 032, India E‐mail: , http://www.jaduniv.edu.in/profile.php?uid=30
| |
Collapse
|
21
|
Sousa SF, Pinto GRP, Ribeiro AJM, Coimbra JTS, Fernandes PA, Ramos MJ. Comparative analysis of the performance of commonly available density functionals in the determination of geometrical parameters for copper complexes. J Comput Chem 2013; 34:2079-90. [PMID: 23798313 DOI: 10.1002/jcc.23349] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 05/16/2013] [Accepted: 05/19/2013] [Indexed: 12/26/2022]
Abstract
In this study, a set of 50 transition-metal complexes of Cu(I) and Cu(II), were used in the evaluation of 18 density functionals in geometry determination. In addition, 14 different basis sets were considered, including four commonly used Pople's all-electron basis sets; four basis sets including popular types of effective-core potentials: Los Alamos, Steven-Basch-Krauss, and Stuttgart-Dresden; and six triple-ζ basis sets. The results illustrate the performance of different methodological alternatives for the treatment of geometrical properties in relevant copper complexes, pointing out Double-Hybrid (DH) and Long-range Correction (LC) Generalized Gradient Approximation (GGA) methods as better descriptors of the geometry of the evaluated systems. These however, are associated with a computational cost several times higher than some of the other methods employed, such as the M06 functional, which has also demonstrated a comparable performance. Regarding the basis sets, 6-31+G(d) and 6-31+G(d,p) were the best performing approaches. In addition, the results show that the use of effective-core potentials has a limited impact, in terms of the accuracy in the determination of metal-ligand bond-lengths and angles in our dataset of copper complexes. Hence, these could become a good alternative for the geometrical description of these systems, particularly CEP-121G and SDD basis sets, if one is considering larger copper complexes where the computational cost could be an issue.
Collapse
Affiliation(s)
- Sérgio F Sousa
- REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | | | | | | | | | | |
Collapse
|
22
|
|
23
|
Petrenko T, Neese F. Efficient and automatic calculation of optical band shapes and resonance Raman spectra for larger molecules within the independent mode displaced harmonic oscillator model. J Chem Phys 2012; 137:234107. [DOI: 10.1063/1.4771959] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|
24
|
Melzer MM, Mossin S, Cardenas AJP, Williams KD, Zhang S, Meyer K, Warren TH. A Copper(II) Thiolate from Reductive Cleavage of an S-Nitrosothiol. Inorg Chem 2012; 51:8658-60. [DOI: 10.1021/ic301356h] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marie M. Melzer
- Department of Chemistry, Georgetown University, Box 571227-1227,
Washington, D.C. 20057, United States
| | - Susanne Mossin
- Department of Chemistry
and Pharmacy, Friedrich-Alexander-University, Erlangen-Nuremberg, Egerlandstrasse 1, 91058 Erlangen,
Germany
| | - Allan Jay P. Cardenas
- Department of Chemistry, Georgetown University, Box 571227-1227,
Washington, D.C. 20057, United States
| | - Kamille D. Williams
- Department of Chemistry, Georgetown University, Box 571227-1227,
Washington, D.C. 20057, United States
| | - Shiyu Zhang
- Department of Chemistry, Georgetown University, Box 571227-1227,
Washington, D.C. 20057, United States
| | - Karsten Meyer
- Department of Chemistry
and Pharmacy, Friedrich-Alexander-University, Erlangen-Nuremberg, Egerlandstrasse 1, 91058 Erlangen,
Germany
| | - Timothy H. Warren
- Department of Chemistry, Georgetown University, Box 571227-1227,
Washington, D.C. 20057, United States
| |
Collapse
|
25
|
Gennari M, Gerey B, Hall N, Pécaut J, Vezin H, Collomb MN, Orio M, Duboc C. Structural, spectroscopic and redox properties of a mononuclear CoII thiolate complex – the reactivity toward S-alkylation: an experimental and theoretical study. Dalton Trans 2012; 41:12586-94. [DOI: 10.1039/c2dt31222k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
26
|
Ho YM, Koo CK, Wong KL, Kong HK, Chan CTL, Kwok WM, Chow CF, Lam MHW, Wong WY. The synthesis and photophysical studies of cyclometalated Pt(ii) complexes with C,N,N-ligands containing imidazolyl donors. Dalton Trans 2012; 41:1792-800. [DOI: 10.1039/c1dt11037c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
27
|
Type 1 copper site synthetic model complexes with increased redox potentials. J Biol Inorg Chem 2011; 17:285-91. [PMID: 21960257 DOI: 10.1007/s00775-011-0849-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 09/19/2011] [Indexed: 10/17/2022]
Abstract
Reactions of NaSCPh(3) with (R(3)tacn)Cu(OTf)(2) (R is Me, iPr; tacn is 1,4,7-triazacyclononane; OTf is CF(3)SO(3)(-)) yield blue complexes identified as ((R(3)tacn)CuSCPh(3))(OTf) on the basis of UV-vis, resonance Raman, and electron paramagnetic resonance (EPR) spectroscopy and electrospray ionization mass spectrometry. These complexes exhibit spectroscopic properties typical of type 1 copper sites in proteins, including diagnostic Sπ → Cu(d(x(2)-y(2))) ligand-to-metal charge transfer transitions at approximately 610-630 nm and small A(||) values in EPR spectra of less than 100 × 10(-4) cm(-1). Cyclic voltammetry experiments revealed redox potentials for the complexes similar to those of several low-potential type 1 copper proteins (e.g., azurin, stellacyanin) and approximately 0.5 V higher than those of previously reported model compounds. Thus, the new complexes mimic key aspects of both the structure and the function of type 1 copper sites.
Collapse
|
28
|
Half-sandwich scorpionate nickel complexes with aliphatic dicarboxylic acid co-ligands. TRANSIT METAL CHEM 2011. [DOI: 10.1007/s11243-011-9511-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
29
|
Besley NA, Robinson D. Theoretical simulation of the spectroscopy and dynamics of a red copper protein. Faraday Discuss 2011; 148:55-70; discussion 97-108. [DOI: 10.1039/c004231e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
30
|
Melzer M, Mossin S, Dai X, Bartell A, Kapoor P, Meyer K, Warren T. A Three-Coordinate Copper(II) Amide from Reductive Cleavage of a Nitrosamine. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200905171] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
31
|
Melzer M, Mossin S, Dai X, Bartell A, Kapoor P, Meyer K, Warren T. A Three-Coordinate Copper(II) Amide from Reductive Cleavage of a Nitrosamine. Angew Chem Int Ed Engl 2009; 49:904-7. [DOI: 10.1002/anie.200905171] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
32
|
Chattopadhyay S, Deb T, Petersen JL, Young VG, Jensen MP. Steric Titration of Arylthiolate Coordination Modes at Pseudotetrahedral Nickel(II) Centers. Inorg Chem 2009; 49:457-67. [DOI: 10.1021/ic901347p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Tapash Deb
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701
| | - Jeffrey L. Petersen
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Victor G. Young
- X-ray Crystallographic Laboratory, Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Michael P. Jensen
- Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701
| |
Collapse
|
33
|
Copper(II) nitrato and chloro complexes with sterically hindered tridentate ligands: Influence of ligand framework and charge on their structure and physicochemical properties. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
34
|
Pettinari C, Marchetti F, Pettinari R, Marinelli A, Crispini A, Bellusci A. A sterically hindered tetrakis(pyrazolyl)borate: Synthesis, characterization and coordinative behaviour. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2009.05.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
35
|
Ghosh S, Cirera J, Vance MA, Ono T, Fujisawa K, Solomon EI. Spectroscopic and electronic structure studies of phenolate Cu(II) complexes: phenolate ring orientation and activation related to cofactor biogenesis. J Am Chem Soc 2009; 130:16262-73. [PMID: 18998639 DOI: 10.1021/ja8044986] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A combination of spectroscopies and DFT calculations have been used to define the electronic structures of two crystallographically defined Cu(II)-phenolate complexes. These complexes differ in the orientation of the phenolate ring which results in different bonding interactions of the phenolate donor orbitals with the Cu(II), which are reflected in the very different spectroscopic properties of the two complexes. These differences in electronic structures lead to significant differences in DFT calculated reactivities with oxygen. These calculations suggest that oxygen activation via a Cu(I) phenoxyl ligand-to-metal charge transfer complex is highly endergonic (>50 kcal/mol), hence an unlikely pathway. Rather, the two-electron oxidation of the phenolate forming a bridging Cu(II) peroxoquinone complex is more favorable (11.3 kcal/mol). The role of the oxidized metal in mediating this two-electron oxidation of the coordinated phenolate and its relevance to the biogenesis of the covalently bound topa quinone in amine oxidase are discussed.
Collapse
Affiliation(s)
- Somdatta Ghosh
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | | | | | | | | | | |
Collapse
|
36
|
Besley NA, Gilbert ATB, Gill PMW. Self-consistent-field calculations of core excited states. J Chem Phys 2009; 130:124308. [DOI: 10.1063/1.3092928] [Citation(s) in RCA: 213] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
37
|
Ghosh S, Dey A, Sun Y, Scholes CP, Solomon EI. Spectroscopic and computational studies of nitrite reductase: proton induced electron transfer and backbonding contributions to reactivity. J Am Chem Soc 2009; 131:277-88. [PMID: 19053185 DOI: 10.1021/ja806873e] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A combination of spectroscopy and DFT calculations has been used to define the geometric and electronic structure of the nitrite bound type 2 (T2) copper site at high and low pH in nitrite reductase from Rhodobacter sphaeroides. At high pH there is no electron transfer from reduced type 1 (T1) to the nitrite bound T2 copper, while protonation triggers T1 --> T2 electron transfer and generation of NO. The DFT calculated reaction coordinate for the N-O bond cleavage in nitrite reduction by the reduced T2 copper suggests that the process is best described as proton transfer triggering electron transfer. Bidentate nitrite binding to copper is calculated to play a major role in activating the reductive cleavage of the nitrite bond through backbonding combined with stabilization of the (-)OH product by coordination to the Cu(2+).
Collapse
Affiliation(s)
- Somdatta Ghosh
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
| | | | | | | | | |
Collapse
|
38
|
Kazi AB, Rasika Dias HV, Tekarli SM, Morello GR, Cundari TR. Coinage Metal−Ethylene Complexes Supported by Tris(pyrazolyl)borates: A Computational Study. Organometallics 2009. [DOI: 10.1021/om8010454] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Abul B. Kazi
- Department of Chemistry, University of Arkansas-Pine Bluff, Pine Bluff, Arkansas 71601, Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, Texas 76019-0065, and Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Box 305070, Denton, Texas 76203-5070
| | - H. V. Rasika Dias
- Department of Chemistry, University of Arkansas-Pine Bluff, Pine Bluff, Arkansas 71601, Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, Texas 76019-0065, and Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Box 305070, Denton, Texas 76203-5070
| | - Sammer M. Tekarli
- Department of Chemistry, University of Arkansas-Pine Bluff, Pine Bluff, Arkansas 71601, Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, Texas 76019-0065, and Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Box 305070, Denton, Texas 76203-5070
| | - Glenn R. Morello
- Department of Chemistry, University of Arkansas-Pine Bluff, Pine Bluff, Arkansas 71601, Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, Texas 76019-0065, and Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Box 305070, Denton, Texas 76203-5070
| | - Thomas R. Cundari
- Department of Chemistry, University of Arkansas-Pine Bluff, Pine Bluff, Arkansas 71601, Department of Chemistry and Biochemistry, The University of Texas at Arlington, 700 Planetarium Place, Arlington, Texas 76019-0065, and Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Box 305070, Denton, Texas 76203-5070
| |
Collapse
|
39
|
Besley NA, Peach MJG, Tozer DJ. Time-dependent density functional theory calculations of near-edge X-ray absorption fine structure with short-range corrected functionals. Phys Chem Chem Phys 2009; 11:10350-8. [DOI: 10.1039/b912718f] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
40
|
Jian FF, Huang LH, Huang BX, Wang J, Wang X. The nanoscale drum-gong-cymbal-like mixed-valence CuIICuI3 cluster polymer and magnetism study. CrystEngComm 2009. [DOI: 10.1039/b904818a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
41
|
Pavelka M, Burda JV. Computational study of redox active centres of blue copper proteins: a computational DFT study. Mol Phys 2008. [DOI: 10.1080/00268970802672684] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
42
|
Brines LM, Villar-Acevedo G, Kitagawa T, Swartz RD, Lugo-Mas P, Kaminsky W, Benedict JB, Kovacs JA. Comparison of Structurally-Related Alkoxide, Amine, and Thiolate-Ligated M (M= Fe, Co) Complexes: the Influence of Thiolates on the Properties of Biologically Relevant Metal Complexes. Inorganica Chim Acta 2008; 361:1070-1078. [PMID: 21731109 DOI: 10.1016/j.ica.2007.07.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mechanistic pathways of metalloenzymes are controlled by the metal ion's electronic and magnetic properties, which are tuned by the coordinated ligands. The functional advantage gained by incorporating cysteinates into the active site of non-heme iron enzymes such as superoxide reductase (SOR) is not entirely understood. Herein we compare the structural and redox properties of a series of structurally-related thiolate, alkoxide, and amine-ligated Fe(II) complexes in order to determine how the thiolate influences properties critical to function. Thiolates are shown to reduce metal ion Lewis acidity relative to alkoxides and amines, and have a strong trans influence thereby helping to maintain an open coordination site. Comparison of the redox potentials of the structurally analogous compounds described herein indicates that alkoxide ligands favor the higher-valent Fe(3+) oxidation state, amine ligands favor the reduced Fe(2+) oxidation state, and thiolates fall somewhere in between. These properties provide a functional advantange for substrate reducing enzymes in that they provide a site at the metal ion for substrate to bind, and a moderate potential that facilitates both substrate reduction, and regeneration of the catalytically active reduced state. Redox potentials for structurally-related Co(II) complexes are shown to be cathodically-shifted relative to their Fe(II) analogues, making them ineffective reducing agents for substrates such as superoxide.
Collapse
Affiliation(s)
- Lisa M Brines
- The Department of Chemistry, University of Washington: Box 351700 Seattle, WA 98195-1700
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Fujisawa K, Kakizaki T, Miyashita Y, Okamoto KI. Structural and spectroscopic comparison of five-coordinate cobalt(II) and nickel(II) thiolato complexes with the related four-coordinate complexes. Inorganica Chim Acta 2008. [DOI: 10.1016/j.ica.2007.08.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
44
|
Pavelka M, Shukla MK, Leszczynski J, Burda JV. Theoretical Study of Hydrated Copper(II) Interactions with Guanine: A Computational Density Functional Theory Study. J Phys Chem A 2008; 112:256-67. [DOI: 10.1021/jp074891+] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
45
|
Pavelka M, Simanek M, Sponer J, Burda JV. Copper Cation Interactions with Biologically Essential Types of Ligands: A Computational DFT Study. J Phys Chem A 2006; 110:4795-809. [PMID: 16599448 DOI: 10.1021/jp056868z] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This work presents a systematic theoretical study on Cu(I) and Cu(II) cations in variable hydrogen sulfide-aqua-ammine ligand fields. These ligands model the biologically most common environment for Cu ions. Molecular structures of the complexes were optimized at the density functional theory (DFT) level. Subsequent thorough energy analyses revealed the following trends: (i) The ammine complexes are the most stable, followed by those containing the aqua and hydrogen sulfide ligands, which are characterized by similar stabilization energies. (ii) The most preferred Cu(I) coordination number is 2 in ammine or aqua ligand fields. A qualitatively different binding picture was obtained for complexes with H(2)S ligands where the 4-coordination is favored. (iii) The 4- and 5-coordinated structures belong to the most stable complexes for Cu(II), regardless of the ligand types. Vertical and adiabatic ionization potentials of Cu(I) complexes were calculated. Charge distribution (using the natural population analysis (NPA) method) and molecular orbital analyses were performed to elucidate the nature of bonding in the examined systems. The results provide in-depth insight into the Cu-binding properties and can be, among others, used for the calibration of bioinorganic force fields.
Collapse
Affiliation(s)
- Matej Pavelka
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | | | | | | |
Collapse
|
46
|
Iijima K, Sunaga T, Hirose M, Saito T. Synthesis and Characterization of Rhenium−Copper Sulfide Cluster Complexes [(Ph3P)2N][Re3(CuX)(μ3-S)4Cl6(PMe2Ph)3] (X = Cl, Br, I). Inorg Chem 2006; 45:3452-5. [PMID: 16602806 DOI: 10.1021/ic052135h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of a trinuclear rhenium sulfide cluster compound Re3S7Cl7 with dimethylphenylphosphine and CuX2 (X = Cl or Br) or CuX (X = Cl, Br, or I) formed tetranuclear cluster complexes [(Ph3P)2N][Re3(CuX)(mu3-S)4Cl6(PMe2Ph)3] (X = Cl, Br, or I). Their solutions have the characteristic intense blue color with visible spectral bands near 600 nm. Single-crystal X-ray structures show that three mu-S atoms in the intermediate trinuclear rhenium complex coordinate to a copper atom, forming elongated tetrahedral structures in which Re-Cu bonding interaction is negligible (Re-Cu distances are 3.50 to approximately 3.54 A as compared with Re-Re distances ranging from 2.69 to 2.81 A).
Collapse
Affiliation(s)
- Kazuya Iijima
- Department of Chemistry, Faculty of Science, Kanagawa University, Hiratsuka, Kanagawa 259-1293, Japan
| | | | | | | |
Collapse
|
47
|
Sakurai T. The alkaline transition of blue copper proteins,Cucumis sativusplastocyanin andPseudomonas aeruginosaazurin. FEBS Lett 2006; 580:1729-32. [PMID: 16500649 DOI: 10.1016/j.febslet.2006.02.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Revised: 02/10/2006] [Accepted: 02/13/2006] [Indexed: 11/26/2022]
Abstract
Autoreduction of Cucumis sativus plastocyanin and Pseudomonas aeruginosa azurin took place at alkaline pHs, having been accompanied by the decrease in the intensities of the charge transfer band, Cys-S- (pi)-->Cu(II) at 597 and 626 nm, and the Cu(II)-EPR signals with small AII values of 6.5 x 10(-3) and 5.3 x 10(-3) cm(-1) for plastocyanin and azurin, respectively. Further, an extra Cu(II)-EPR signal with a large AII value of 21 x 10(-3) cm(-1) also reversibly emerged with increasing pH. Plastocyanin and azurin are in an equilibrium of the three forms at alkaline pHs.
Collapse
Affiliation(s)
- Takeshi Sakurai
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan.
| |
Collapse
|
48
|
Tolman WB. Using synthetic chemistry to understand copper protein active sites: a personal perspective. J Biol Inorg Chem 2006; 11:261-71. [PMID: 16447049 DOI: 10.1007/s00775-006-0078-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 01/03/2006] [Indexed: 10/25/2022]
Abstract
The results of studies performed in the author's laboratory are surveyed, with particular emphasis on demonstrating the value of a multidisciplinary synthetic modeling approach for discovering new and unusual chemistry helpful for understanding the properties of the active sites of copper proteins or assessing the feasibility of mechanistic pathways they might follow during catalysis. The discussion focuses on the progress made to date toward comprehending the nitrite reductase catalytic site and mechanism, the electronic structures of copper thiolate electron transfer centers, the sulfido-bridged "CuZ" site in nitrous oxide reductase, and the processes of dioxygen binding and activation by mono- and dicopper centers in oxidases and oxygenases.
Collapse
Affiliation(s)
- William B Tolman
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA.
| |
Collapse
|
49
|
Hattori S, Wada Y, Yanagida S, Fukuzumi S. Blue copper model complexes with distorted tetragonal geometry acting as effective electron-transfer mediators in dye-sensitized solar cells. J Am Chem Soc 2005; 127:9648-54. [PMID: 15984893 DOI: 10.1021/ja0506814] [Citation(s) in RCA: 267] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electron self-exchange rate constants of blue copper model complexes, [(-)-sparteine-N,N'](maleonitriledithiolato-S,S')copper ([Cu(SP)(mmt)])(0/)(-), bis(2,9-dimethy-1,10-phenanthroline)copper ([Cu(dmp)(2)](2+/+)), and bis(1,10-phenanthroline)copper ([Cu(phen)(2)](2+/+)) have been determined from the rate constants of electron transfer from a homologous series of ferrocene derivatives to the copper(II) complexes in light of the Marcus theory of electron transfer. The resulting electron self-exchange rate constant increases in the order: [Cu(phen)(2)](2+/+) < [Cu(SP)(mmt)](0/)(-) < [Cu(dmp)(2)](2+/+), in agreement with the order of the smaller structural change between the copper(II) and copper(I) complexes due to the distorted tetragonal geometry. The dye-sensitized solar cells (DSSC) were constructed using the copper complexes as redox couples to compare the photoelectrochemical responses with those using the conventional I(3)(-)/I(-) couple. The light energy conversion efficiency (eta) values under illumination of simulated solar light irradiation (100 mW/cm(2)) of DSSCs using [Cu(phen)(2)](2+/+), [Cu(dmp)(2)](2+/+), and [Cu(SP)(mmt)](0/)(-) were recorded as 0.1%, 1.4%, and 1.3%, respectively. The maximum eta value (2.2%) was obtained for a DSSC using the [Cu(dmp)(2)](2+/+) redox couple under the light irradiation of 20 mW/cm(2) intensity, where a higher open-circuit voltage of the cell was attained as compared to that of the conventional I(3)(-)/I(-) couple.
Collapse
Affiliation(s)
- Shigeki Hattori
- Department of Material and Life Science, Graduate School of Engineering, Osaka University, SORST, Japan
| | | | | | | |
Collapse
|
50
|
Gorelsky SI, Basumallick L, Vura-Weis J, Sarangi R, Hodgson KO, Hedman B, Fujisawa K, Solomon EI. Spectroscopic and DFT investigation of [M{HB(3,5-iPr2pz)3}(SC6F5)] (M = Mn, Fe, Co, Ni, Cu, and Zn) model complexes: periodic trends in metal-thiolate bonding. Inorg Chem 2005; 44:4947-60. [PMID: 15998022 PMCID: PMC2593087 DOI: 10.1021/ic050371m] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of metal-varied [ML(SC6F5)] model complexes (where L = hydrotris(3,5-diisopropyl-1-pyrazolyl)borate and M = Mn, Fe, Co, Ni, Cu, and Zn) related to blue copper proteins has been studied by a combination of absorption, MCD, resonance Raman, and S K-edge X-ray absorption spectroscopies. Density functional calculations have been used to characterize these complexes and calculate their spectra. The observed variations in geometry, spectra, and bond energies are interpreted in terms of changes in the nature of metal-ligand bonding interactions. The metal 3d-ligand orbital interaction, which contributes to covalent bonding in these complexes, becomes stronger going from Mn(II) to Co(II) (the sigma contribution) and to Cu(II) (the pi contribution). This change in the covalency results from the increased effective nuclear charge of the metal atom in going from Mn(II) to Zn(II) and the change in the 3d orbital populations (d5-->d10). Ionic bonding also plays an important role in determining the overall strength of the ML(+)-SC6F5(-) interaction. However, there is a compensating effect: as the covalent contribution to the metal-ligand bonding increases, the ionic contribution decreases. These results provide insight into the Irving-Williams series, where it is found that the bonding of the ligand being replaced by the thiolate makes a major contribution to the observed order of the stability constants over the series of metal ions.
Collapse
Affiliation(s)
| | | | - Josh Vura-Weis
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | | | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309
| | - Britt Hedman
- Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309
| | - Kiyoshi Fujisawa
- Department of Chemistry, University of Tsukuba, Tsukuba 305-8571 Japan
| | | |
Collapse
|