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Palopoli C, Ferreyra J, Conte-Daban A, Richezzi M, Foi A, Doctorovich F, Anxolabéhère-Mallart E, Hureau C, Signorella SR. Insights into Second-Sphere Effects on Redox Potentials, Spectroscopic Properties, and Superoxide Dismutase Activity of Manganese Complexes with Schiff-Base Ligands. ACS OMEGA 2019; 4:48-57. [PMID: 31459311 PMCID: PMC6649300 DOI: 10.1021/acsomega.8b03018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/20/2018] [Indexed: 05/04/2023]
Abstract
Six Mn-Schiff base complexes, [Mn(X-salpn)]0/+ (salpn = 1,3-bis(sal-ic-ylidenamino)propane, X = H [1], 5-Cl [2], 2,5-F2 [3], 3,5-Cl2 [4], 5-NO2 [5], 3,5-(NO2)2 [6]), were synthesized and characterized in solution, and second-sphere effects on their electrochemical and spectroscopic properties were analyzed. The six complexes catalyze the dismutation of superoxide with catalytic rate constants in the range 0.65 to 1.54 × 106 M-1 s-1 obtained through the nitro blue tetrazolium photoreduction inhibition superoxide dismutases assay, in aqueous medium of pH 7.8. In solution, these compounds possess two labile solvent molecules in the axial positions favoring coordination of the highly nucleophilic O2 •- to the metal center. Even complex 5, [Mn(5-(NO2)salpn) (OAc) (H2O)], with an axial acetate in the solid state, behaves as a 1:1 electrolyte in methanolic solution. Electron paramagnetic resonance and UV-vis monitoring of the reaction of [Mn(X-salpn)]0/+ with KO2 demonstrates that in diluted solutions these complexes behave as catalysts supporting several additions of excess O2 •-, but at high complex concentrations (≥0.75 mM) catalyst self-inhibition occurs by the formation of a catalytically inactive dimer. The correlation of spectroscopic, electrochemical, and kinetics data suggest that second-sphere effects control the oxidation states of Mn involved in the O2 •- dismutation cycle catalyzed by complexes 1-6 and modulate the strength of the Mn-substrate adduct for electron-transfer through an inner-sphere mechanism.
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Affiliation(s)
- Claudia Palopoli
- IQUIR
(Instituto de Química Rosario), Consejo Nacional de Investigaciones
Científicas y Técnicas (CONICET), Facultad de Ciencias
Bioquímicas y Farmacéuticas, Universidad Nacional de
Rosario, Suipacha 531, S2002LRK Rosario, Argentina
| | - Joaquín Ferreyra
- IQUIR
(Instituto de Química Rosario), Consejo Nacional de Investigaciones
Científicas y Técnicas (CONICET), Facultad de Ciencias
Bioquímicas y Farmacéuticas, Universidad Nacional de
Rosario, Suipacha 531, S2002LRK Rosario, Argentina
| | | | - Micaela Richezzi
- IQUIR
(Instituto de Química Rosario), Consejo Nacional de Investigaciones
Científicas y Técnicas (CONICET), Facultad de Ciencias
Bioquímicas y Farmacéuticas, Universidad Nacional de
Rosario, Suipacha 531, S2002LRK Rosario, Argentina
| | - Ana Foi
- Departamento
de Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires, Argentina
| | - Fabio Doctorovich
- Departamento
de Química Inorgánica, Analítica y Química
Física/INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires, Argentina
| | - Elodie Anxolabéhère-Mallart
- Laboratoire
d’Electrochimie Moléculaire UMR CNRS-P7 7591, Université
Paris Diderot-Paris, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Christelle Hureau
- LCC-CNRS,
Université de Toulouse, 205 route de Narbonne, 31077 Toulouse, France
| | - Sandra R. Signorella
- IQUIR
(Instituto de Química Rosario), Consejo Nacional de Investigaciones
Científicas y Técnicas (CONICET), Facultad de Ciencias
Bioquímicas y Farmacéuticas, Universidad Nacional de
Rosario, Suipacha 531, S2002LRK Rosario, Argentina
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Synthesis and electron paramagnetic resonance studies of seven coordinated Mn(II) complexes with tridentate N-donor ligands. Polyhedron 2018. [DOI: 10.1016/j.poly.2018.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Yang Y, Zhong W, Nie B, Chen J, Wei Z, Liu X. Synergetic oxidation of ethylbenzene to acetophenone catalyzed by manganese(II) complexes bearing pendant iodophenyl groups. J Organomet Chem 2017. [DOI: 10.1016/j.jorganchem.2017.10.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Zhang XT, Wang S, Xing GW. Boronlectin/Polyelectrolyte Ensembles as Artificial Tongue: Design, Construction, and Application for Discriminative Sensing of Complex Glycoconjugates from Panax ginseng. ACS APPLIED MATERIALS & INTERFACES 2017; 9:3368-3375. [PMID: 28071886 DOI: 10.1021/acsami.6b13363] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Ginsenoside is a large family of triterpenoid saponins from Panax ginseng, which possesses various important biological functions. Due to the very similar structures of these complex glycoconjugates, it is crucial to develop a powerful analytic method to identify ginsenosides qualitatively or quantitatively. We herein report an eight-channel fluorescent sensor array as artificial tongue to achieve the discriminative sensing of ginsenosides. The fluorescent cross-responsive array was constructed by four boronlectins bearing flexible boronic acid moieties (FBAs) with multiple reactive sites and two linear poly(phenylene-ethynylene) (PPEs). An "on-off-on" response pattern was afforded on the basis of superquenching of fluorescent indicator PPEs and an analyte-induced allosteric indicator displacement (AID) process. Most importantly, it was found that the canonical distribution of ginsenoside data points analyzed by linear discriminant analysis (LDA) was highly correlated with the inherent molecular structures of the analytes, and the absence of overlaps among the five point groups reflected the effectiveness of the sensor array in the discrimination process. Almost all of the unknown ginsenoside samples at different concentrations were correctly identified on the basis of the established mathematical model. Our current work provided a general and constructive method to improve the quality assessment and control of ginseng and its extracts, which are useful and helpful for further discriminating other complex glycoconjugate families.
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Affiliation(s)
- Xiao-Tai Zhang
- Department of Chemistry, Beijing Normal University , Beijing 100875, China
| | - Shu Wang
- Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China
| | - Guo-Wen Xing
- Department of Chemistry, Beijing Normal University , Beijing 100875, China
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Abstract
EPR spectroscopy combined with quantum chemistry for the investigation of the magnetic anisotropy of MnII, MnIII and MnIV.
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Affiliation(s)
- Carole Duboc
- University Grenoble-Alpes
- CNRS
- UMR 5250
- Département de Chimie Moléculaire
- 38041 Grenoble cedex 9
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Saad A, Zhu W, Rousseau G, Mialane P, Marrot J, Haouas M, Taulelle F, Dessapt R, Serier-Brault H, Rivière E, Kubo T, Oldfield E, Dolbecq A. Polyoxomolybdate Bisphosphonate Heterometallic Complexes: Synthesis, Structure, and Activity on a Breast Cancer Cell Line. Chemistry 2015; 21:10537-47. [DOI: 10.1002/chem.201406565] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/12/2015] [Indexed: 01/15/2023]
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Que EL, Bleher R, Duncan FE, Kong BY, Gleber SC, Vogt S, Chen S, Garwin SA, Bayer AR, Dravid V, Woodruff TK, O’Halloran TV. Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks. Nat Chem 2015; 7:130-9. [PMID: 25615666 PMCID: PMC4315321 DOI: 10.1038/nchem.2133] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 11/11/2014] [Indexed: 12/22/2022]
Abstract
Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes.
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Affiliation(s)
- Emily L. Que
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
| | - Reiner Bleher
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
- Northwestern University Atomic and Nanoscale Characterization Experimental Center, Evanston, IL 60208, USA
| | - Francesca E. Duncan
- Department of Obstetrics and Gynecology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Betty Y. Kong
- Department of Obstetrics and Gynecology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sophie C. Gleber
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Stefan Vogt
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Si Chen
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Seth A. Garwin
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Amanda R. Bayer
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Vinayak Dravid
- Northwestern University Atomic and Nanoscale Characterization Experimental Center, Evanston, IL 60208, USA
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
- Department of Materials Science and Engineering, Northwestern University; Evanston, IL 60208, USA
| | - Teresa K. Woodruff
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
- Department of Obstetrics and Gynecology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Thomas V. O’Halloran
- The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
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Gerey B, Gennari M, Gouré E, Pécaut J, Blackman A, Pantazis DA, Neese F, Molton F, Fortage J, Duboc C, Collomb MN. Calcium and heterometallic manganese–calcium complexes supported by tripodal pyridine-carboxylate ligands: structural, EPR and theoretical investigations. Dalton Trans 2015; 44:12757-70. [DOI: 10.1039/c5dt01776a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rare examples of heteronuclear μ-carboxylato bridged Mn–Ca complexes are reported.
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Affiliation(s)
- Bertrand Gerey
- Univ. Grenoble Alpes
- F-38000 Grenoble
- France
- CNRS
- F-38000 Grenoble
| | | | - Eric Gouré
- Univ. Grenoble Alpes
- F-38000 Grenoble
- France
- CNRS
- F-38000 Grenoble
| | | | - Allan Blackman
- School of Applied Sciences
- Auckland University of Technology
- Auckland 1142
- New Zealand
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für Chemische Energie Konversion
- D-45470 Mülheim an der Ruhr
- Germany
| | - Frank Neese
- Max-Planck-Institut für Chemische Energie Konversion
- D-45470 Mülheim an der Ruhr
- Germany
| | - Florian Molton
- Univ. Grenoble Alpes
- F-38000 Grenoble
- France
- CNRS
- F-38000 Grenoble
| | - Jérôme Fortage
- Univ. Grenoble Alpes
- F-38000 Grenoble
- France
- CNRS
- F-38000 Grenoble
| | - Carole Duboc
- Univ. Grenoble Alpes
- F-38000 Grenoble
- France
- CNRS
- F-38000 Grenoble
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Panja A. Selective coordination of multidentate ligands in manganese(II) complexes: Syntheses, structures and phenoxazinone synthase mimicking activity. Polyhedron 2014. [DOI: 10.1016/j.poly.2014.05.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Panja A. Metal ionic size directed complexation in manganese(ii) coordination chemistry: efficient candidates showing phenoxazinone synthase mimicking activity. RSC Adv 2014. [DOI: 10.1039/c4ra03427a] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Influence of the ionic size of metal on the diverse coordination chemistry of manganese(ii) has been examined by X-ray diffraction and IR spectral studies, and their relative phenoxazinone synthase activity has also been explored.
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Affiliation(s)
- Anangamohan Panja
- Postgraduate Department of Chemistry
- Panskura Banamali College
- Panskura RS, India
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Jiang W, Gorden JD, Goldsmith CR. Catalysis of Alkene Epoxidation by a Series of Gallium(III) Complexes with Neutral N-Donor Ligands. Inorg Chem 2013; 52:5814-23. [DOI: 10.1021/ic400570h] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wenchan Jiang
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - John D. Gorden
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Christian R. Goldsmith
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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Ségaud N, Rebilly JN, Sénéchal-David K, Guillot R, Billon L, Baltaze JP, Farjon J, Reinaud O, Banse F. Iron Coordination Chemistry with New Ligands Containing Triazole and Pyridine Moieties. Comparison of the Coordination Ability of the N-Donors. Inorg Chem 2013; 52:691-700. [DOI: 10.1021/ic301834x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Nathalie Ségaud
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Jean-Noël Rebilly
- Laboratoire de Chimie et de
Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, CNRS UMR 8601, F-75270 Paris Cedex
06, France
| | - Katell Sénéchal-David
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Régis Guillot
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Laurianne Billon
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Jean-Pierre Baltaze
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Jonathan Farjon
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Olivia Reinaud
- Laboratoire de Chimie et de
Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, CNRS UMR 8601, F-75270 Paris Cedex
06, France
| | - Frédéric Banse
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
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El Ghachtouli S, Vincent Ching HY, Lassalle-Kaiser B, Guillot R, Leto DF, Chattopadhyay S, Jackson TA, Dorlet P, Anxolabéhère-Mallart E. Electrochemical formation of MnIII-peroxo complexes supported by pentadentate amino pyridine and imidazole ligands. Chem Commun (Camb) 2013; 49:5696-8. [DOI: 10.1039/c3cc41300d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bortoluzzi AJ, Terra GG. 2,2′-{[2-(Pyridin-2-yl)-1,3-diazinane-1,3-diyl]bis(methylene)}diphenol. Acta Crystallogr Sect E Struct Rep Online 2012; 68:o2744. [PMID: 22969627 PMCID: PMC3435756 DOI: 10.1107/s1600536812035477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 08/10/2012] [Indexed: 11/10/2022]
Abstract
The title compound, C23H25N3O2, was obtained as an intermediary in the preparation of non-symmetric tertiary diamines. The molecular structure presents T-shaped spatial form, in which the pyrimidine ring exhibits a chair conformation. The pyridyl ring is almost perpendicular to the phenyl rings with dihedral angles of 80.17 (8) and 76.03 (2)°. The phenol and amine groups are involved in two strong intramolecular O—H⋯N interactions. In the crystal, the molecules are stacked along [010]; however, no intermolecular interactions are observed.
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Geiger RA, Leto DF, Chattopadhyay S, Dorlet P, Anxolabéhère-Mallart E, Jackson TA. Geometric and Electronic Structures of Peroxomanganese(III) Complexes Supported by Pentadentate Amino-Pyridine and -Imidazole Ligands. Inorg Chem 2011; 50:10190-203. [DOI: 10.1021/ic201168j] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert A. Geiger
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
| | - Domenick F. Leto
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
| | - Swarup Chattopadhyay
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
| | - Pierre Dorlet
- Laboratoire Stress Oxydant et Détoxication, CNRS URA 2096 and CEA/iBiTec-S/SB2SM, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Elodie Anxolabéhère-Mallart
- Laboratoire d’Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Diderot, Sorbonne Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Timothy A. Jackson
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas, Lawrence, Kansas 66045, United States
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Duboc C, Ganyushin D, Sivalingam K, Collomb MN, Neese F. Systematic theoretical study of the zero-field splitting in coordination complexes of Mn(III). Density functional theory versus multireference wave function approaches. J Phys Chem A 2011; 114:10750-8. [PMID: 20828179 DOI: 10.1021/jp107823s] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper presents a detailed evaluation of the performance of density functional theory (DFT) as well as complete active space self-consistent field (CASSCF)-based methods (CASSCF and second-order N-electron valence state perturbation theory, NEVPT2) to predict the zero-field splitting (zfs) parameters for a series of coordination complexes containing the Mn(III) ion. The physical origin of the experimentally determined zfs's was investigated by studying the different contributions to these parameters. To this end, a series of mononuclear Mn(III) complexes was chosen for which the structures have been resolved by X-ray diffraction and the zfs parameters have been accurately determined by high-field EPR spectroscopy. In a second step, small models have been constructed to allow for a systematic assessment of the factors that dominate the variations in the observed zfs parameters and to establish magnetostructural correlations. Among the tested functionals, the best predictions have been obtained with B3LYP, followed by the nonhybrid BP86 functional, which in turn is more successful than the meta-hybrid GGA functional TPSSh. For the estimation of the spin-orbit coupling (SOC) part of the zfs, it was found that the coupled perturbed SOC approach CP is more successful than the Pederson-Khanna method. Concerning the spin-spin interaction (SS), the restricted open-shell Kohn-Sham (ROKS) approach led to a slightly better agreement with the experiment than the unrestricted KS (UKS) approach. The ab initio state-averaged CASSCF (SA-CASSCF) method with a minimal active space and the most recent implementation that treats the SOC and SS contributions on an equal footing provides the best predictions for the zfs. The analysis demonstrates that the major contribution to the axial zfs parameter (D) originates from the SOC interaction but that the SS part is far from being negligible (between 10 and 20% of D). Importantly, the various excited triplet ligand field states account for roughly half of the value of D, contrary to popular ligand field models. Despite covering dynamic correlation contributions to the transition energies, NEVPT2 does not lead to large improvements in the results as the excitation energies of the Mn(III) d-d transitions are already fairly accurate at the SA-CASSCF level. For a given type of coordination sphere (e.g., elongated or compressed octahedron), the magnetic anisotropy of the Mn(III) ion, D, does not appear to be highly sensitive to the nature of the ligands, while the E/D ratio is notably affected by all octahedral distortions. Furthermore, the introduction of different halides into the coordination sphere of Mn(III) only leads to small effects on D. Nevertheless, it appears that oxygen-based ligands afford larger D values than nitrogen-based ligands.
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Affiliation(s)
- Carole Duboc
- Département de Chimie Moléculaire, UMR-5250, Laboratoire de Chimie Inorganique Redox, Institut de Chimie Moléculaire de Grenoble FR- CNRS-2607, Université Joseph Fourier Grenoble 1/CNRS, BP-53, 38041 Grenoble Cedex 9, France.
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Nippe M, Wang J, Bill E, Hope H, Dalal NS, Berry JF. Crystals in which some metal atoms are more equal than others: inequalities from crystal packing and their spectroscopic/magnetic consequences. J Am Chem Soc 2011; 132:14261-72. [PMID: 20860382 DOI: 10.1021/ja106510g] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Crystal structures of the heterometallic compounds CrCrFe(dpa)(4)Cl(2) (1), CrCrMn(dpa)(4)Cl(2) (2), and MoMoMn(dpa)(4)Cl(2) (3) (dpa = 2,2'-dipyridylamide) show disorder in the metal atom positions such that the linear M(A)[quadruple bond]M(A)···M(B) array for a given molecule in the crystal is oriented in one of two opposing directions. Despite the fact that the direct coordination sphere of the metals in the two crystallographically independent orientations is identical, subtle differences in some metal-ligand bond distances are observed in 1 and 3 due to differences in the orientation of a solvent molecule of crystallization. The Fe(II) and Mn(II) ions serve as sensitive local spectroscopic probes that have been interrogated by Mössbauer spectroscopy and high-field EPR spectroscopy, respectively. The subtle differences in the two independent Fe and Mn sites in 1 and 3 unexpectedly give rise to unusually large differences in the measured Fe quadrupole splitting (ΔE(Q)) in 1 and Mn zero-field splitting (D) in 3. Variable-temperature/single-crystal EPR spectroscopy has allowed us to determine that the temperature-dependent D tensors in 3 are oriented along the metal-metal axis and that they show significantly different dynamic behavior with temperature. The differences in ΔE(Q) and D are reproduced by density functional calculations on truncated models for 1 and 3 that lack the quadruply bonded M(A)[quadruple bond]M(A) groups, though the magnitude of the calculated effect is not as large as that observed experimentally. We suggest that the large observed differences in ΔE(Q) and D for the individual sites could be due to the influence of the strong diamagnetic anisotropy of the quadruply bonded M[quadruple bond]M unit.
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Affiliation(s)
- Michael Nippe
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA
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Stoyanova R, Barra AL, Yoncheva M, Kuzmanova E, Zhecheva E. Local structure of Mn4+ and Fe3+ spin probes in layered LiAlO2 oxide by modelling of zero-field splitting parameters. Dalton Trans 2011; 40:9106-15. [DOI: 10.1039/c1dt10929d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Rich J, Castillo CE, Romero I, Rodríguez M, Duboc C, Collomb MN. Investigation of the Zero-Field Splitting in Six- and Seven-Coordinate Mononuclear MnII Complexes with N/O-Based Ligands by Combining EPR Spectroscopy and Quantum Chemistry. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000373] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lu X, Zhu W, Xie Y, Li X, Gao Y, Li F, Tian H. Near-IR Core-Substituted Naphthalenediimide Fluorescent Chemosensors for Zinc Ions: Ligand Effects on PET and ICT Channels. Chemistry 2010; 16:8355-64. [DOI: 10.1002/chem.201000461] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Mono- and dinuclear manganese(II) complexes derived from the cis/trans isomers of 2,4,5-tris(2-pyridyl)-4,5-dihydroimidazole. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2009.11.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tzima TD, Sioros G, Duboc C, Kovala-Demertzi D, Melissas VS, Sanakis Y. Multifrequency electron paramagnetic resonance and theoretical studies of a Mn(II) (S=5/2) complex: The role of geometrical elements on the Zero Field Splitting parameters. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.07.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Groni S, Hureau C, Guillot R, Blondin G, Blain G, Anxolabéhère-Mallart E. Characterizations of chloro and aqua Mn(II) mononuclear complexes with amino-pyridine ligands. Comparison of their electrochemical properties with those of Fe(II) counterparts. Inorg Chem 2009; 47:11783-97. [PMID: 19007154 DOI: 10.1021/ic8015172] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The solution behavior of mononuclear Mn(II) complexes, namely, [(L(5)(2))MnCl](+) (1), [(L(5)(3))MnCl](+) (2), [(L(5)(2))Mn(OH(2))](2+) (3), [(L(5)(3))Mn(OH(2))](2+) (4), and [(L(6)(2))Mn(OH(2))](2+) (6), with L(5)(2/3) and L(6)(2) being penta- and hexadentate amino-pyridine ligands, is investigated in MeCN using EPR, UV-vis spectroscopies, and electrochemistry. The addition of one chloride ion onto species 6 leads to the formation of the complex [(L(6)(2))MnCl](+) (5) that is X-ray characterized. EPR and UV-vis spectra indicate that structure and redox states of complexes 1-6 are maintained in MeCN solution. Chloro complexes 1, 2, and 5 show reversible Mn(II)/Mn(III) process at 0.95, 1.02, and 1.05 V vs SCE, respectively, whereas solvated complexes 3, 4, and 6 show an irreversible anodic peak around 1.5 V vs SCE. Electrochemical oxidations of 1 and 5 leading to the Mn(III) complexes [(L(5)(2))MnCl](2+) (7) and [(L(6)(2))MnCl](2+) (8) are successful. The UV-vis signatures of 7 and 8 show features associated with chloro to Mn(III) LMCT and d-d transitions. The X-ray characterization of the heptacoordinated Mn(III) species 8 is also reported. The analogous electrochemical generation of the corresponding Mn(III) complex was not possible when starting from 2. The new mixed-valence di-mu-oxo [(L(5)(2))Mn(muO)(2)Mn(L(5)(2))](3+) species (9) can be obtained from 3, whereas the sister [(L(5)(3))Mn(muO)(2)Mn(L(5)(3))](3+) species can not be generated from 4. Such different responses upon oxidations are commented on with the help of comparison with related Mn/Fe complexes and are discussed in relation with the size of the metallacycle formed between the diamino bridge and the metal center (5- vs 6-membered). Lastly, a comparison between redox potentials of the studied Mn(II) complexes with those of Fe(II) analogues is drawn and completed with previously reported data on Mn/Fe isostructural systems. This gives us the opportunity to get some indirect insights into the metal specificity encountered in enzymes among which superoxide dismutase is the archetypal model.
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Affiliation(s)
- Sihem Groni
- Equipe de Chimie Inorganique, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud 11, UMR 8182 CNRS, Orsay F-91405, France
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Duboc C, Collomb MN. Multifrequency high-field EPR investigation of a mononuclear manganese(iv) complex. Chem Commun (Camb) 2009:2715-7. [DOI: 10.1039/b901185d] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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