1
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Wu WY, Zheng WY, Chen WT, Tsai FT, Tsai ML, Pao CW, Chen JL, Liaw WF. Electronic Structure and Transformation of Dinitrosyl Iron Complexes (DNICs) Regulated by Redox Non-Innocent Imino-Substituted Phenoxide Ligand. Inorg Chem 2024; 63:2431-2442. [PMID: 38258796 PMCID: PMC10848267 DOI: 10.1021/acs.inorgchem.3c03367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 01/04/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024]
Abstract
The coupled NO-vibrational peaks [IR νNO 1775 s, 1716 vs, 1668 vs cm-1 (THF)] between two adjacent [Fe(NO)2] groups implicate the electron delocalization nature of the singly O-phenoxide-bridged dinuclear dinitrosyliron complex (DNIC) [Fe(NO)2(μ-ON2Me)Fe(NO)2] (1). Electronic interplay between [Fe(NO)2] units and [ON2Me]- ligand in DNIC 1 rationalizes that "hard" O-phenoxide moiety polarizes iron center(s) of [Fe(NO)2] unit(s) to enforce a "constrained" π-conjugation system acting as an electron reservoir to bestow the spin-frustrated {Fe(NO)2}9-{Fe(NO)2}9-[·ON2Me]2- electron configuration (Stotal = 1/2). This system plays a crucial role in facilitating the ligand-based redox interconversion, working in harmony to control the storage and redox-triggered transport of the [Fe(NO)2]10 unit, while preserving the {Fe(NO)2}9 core in DNICs {Fe(NO)2}9-[·ON2Me]2- [K-18-crown-6-ether)][(ON2Me)Fe(NO)2] (2) and {Fe(NO)2}9-[·ON2Me] [(ON2Me)Fe(NO)2][PF6] (3). Electrochemical studies suggest that the redox interconversion among [{Fe(NO)2}9-[·ON2Me]2-] DNIC 3 ↔ [{Fe(NO)2}9-[ON2Me]-] ↔ [{Fe(NO)2}9-[·ON2Me]] DNIC 2 are kinetically feasible, corroborated by the redox shuttle between O-bridged dimerized [(μ-ONMe)2Fe2(NO)4] (4) and [K-18-crown-6-ether)][(ONMe)Fe(NO)2] (5). In parallel with this finding, the electronic structures of [{Fe(NO)2}9-{Fe(NO)2}9-[·ON2Me]2-] DNIC 1, [{Fe(NO)2}9-[·ON2Me]2-] DNIC 2, [{Fe(NO)2}9-[·ON2Me]] DNIC 3, [{Fe(NO)2}9-[ONMe]-]2 DNIC 4, and [{Fe(NO)2}9-[·ONMe]2-] DNIC 5 are evidenced by EPR, SQUID, and Fe K-edge pre-edge analyses, respectively.
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Affiliation(s)
- Wun-Yan Wu
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wei-Yuan Zheng
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wei-Ting Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Fu-Te Tsai
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ming-Li Tsai
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Chih-Wen Pao
- National Synchrotron Radiation
Research Center, Hsinchu 30013, Taiwan
| | - Jeng-Lung Chen
- National Synchrotron Radiation
Research Center, Hsinchu 30013, Taiwan
| | - Wen-Feng Liaw
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
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2
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Samanta D, Saha P, Maity S, Mondal S, Ghosh P. Coligands Controlled Reactivities of Ruthenium(II) Precursors: Antiferromagnetically Coupled Ruthenium(III)-Phenoxyl versus Ruthenium(II)-Phenoxyl Forms. Inorg Chem 2024; 63:229-246. [PMID: 38141026 DOI: 10.1021/acs.inorgchem.3c03060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
The study disclosed that the reactivities of [RuII (PPh3)3Cl2] and [RuII(PPh3)3(CO)(H)Cl] precursors toward a trimethoxyarylimino-phenol derivative are sensibly different. The former promotes methoxy demethylation reaction affording a [Phenolato-RuIII-Phenolato] unit, while the latter containing π-acidic CO and hydride as coligands leads to C-H activation reaction, generating a [Phenolato-RuII-Aryl] unit. Notably, the oxidized analogues of these two forms produce antiferromagnetically coupled [RuIII-phenoxyl] and paramagnetic [RuII-phenoxyl] forms, which exhibit diverse reactivities. Surprisingly, the magnetically coupled [RuIII-phenoxyl] form obtained from [Phenolato-RuIII-Phenolato] motif leads to coligand, PPh3 oxidation and undergoes dimerization, making a Ru-Ru bond (2.599(2) Å), while the [RuII-phenoxyl] form obtained from [Phenolato-RuII-Aryl] motif leads to C-C coupling and H abstraction reactions. The coupling reaction affords a 4,4'-dibenzosemiquinonate anion radical complex, but the H-abstraction of the phenoxyl form gives a [RuII-Phenol] complex. For comparison, [RuII(IQR 0)] and [RuII(ISQR·-)] complexes were also isolated, where IQR 0 and ISQR·- are p-R-o-iminobenzoquinone and p-R-o-iminobenzosemiquinonate anion radicals. However, they fail to promote any bond-formation reaction. The molecular and electronic structures of the ruthenium (II/III) complexes were confirmed by single-crystal X-ray crystallography, EPR spectroscopy, and DFT calculations.
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Affiliation(s)
- Debasish Samanta
- Department of Chemistry, Ramakrishna Mission Residential College, Narendrapur, Kolkata 700103, India
| | - Pinaki Saha
- Department of Chemistry, Ramakrishna Mission Residential College, Narendrapur, Kolkata 700103, India
| | - Suvendu Maity
- Department of Chemistry, Ramakrishna Mission Residential College, Narendrapur, Kolkata 700103, India
| | - Sudipto Mondal
- Department of Chemistry, Ramakrishna Mission Residential College, Narendrapur, Kolkata 700103, India
| | - Prasanta Ghosh
- Department of Chemistry, Ramakrishna Mission Residential College, Narendrapur, Kolkata 700103, India
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3
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Reversible Redox Processes in Polymer of Unmetalated Salen-Type Ligand: Combined Electrochemical in Situ Studies and Direct Comparison with Corresponding Nickel Metallopolymer. Int J Mol Sci 2022; 23:ijms23031795. [PMID: 35163715 PMCID: PMC8836782 DOI: 10.3390/ijms23031795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 11/17/2022] Open
Abstract
Most non-metalized Salen-type ligands form passivation thin films on electrode surfaces upon electrochemical oxidation. In contrast, the H2(3-MeOSalen) forms electroactive polymer films similarly to the corresponding nickel complex. There are no details of electrochemistry, doping mechanism and charge transfer pathways in the polymers of pristine Salen-type ligands. We studied a previously uncharacterized electrochemically active polymer of a Salen-type ligand H2(3-MeOSalen) by a combination of cyclic voltammetry, in situ ultraviolet-visible (UV-VIS) spectroelectrochemistry, in situ electrochemical quartz crystal microbalance and Fourier Transform infrared spectroscopy (FTIR) spectroscopy. By directly comparing it with the polymer of a Salen-type nickel complex poly-Ni(3-MeOSalen) we elucidate the effect of the central metal atom on the structure and charge transport properties of the electrochemically doped polymer films. We have shown that the mechanism of charge transfer in the polymeric ligand poly-H2(3-MeOSalen) are markedly different from the corresponding polymeric nickel complex. Due to deviation from planarity of N2O2 sphere for the ligand H2(3-MeOSalen), the main pathway of electron transfer in the polymer film poly-H2(3-MeOSalen) is between π-stacked structures (the π-electronic systems of phenyl rings are packed face-to-face) and C-C bonded phenyl rings. The main way of electron transfer in the polymer film poly-Ni(3-MeOSalen) is along the polymer chain, while redox processes are ligand-based.
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4
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Odella E, Moore TA, Moore AL. Tuning the redox potential of tyrosine-histidine bioinspired assemblies. PHOTOSYNTHESIS RESEARCH 2022; 151:185-193. [PMID: 33432530 DOI: 10.1007/s11120-020-00815-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
Photosynthesis powers our planet and is a source of inspiration for developing artificial constructs mimicking many aspects of the natural energy transducing process. In the complex machinery of photosystem II (PSII), the redox activity of the tyrosine Z (Tyrz) hydrogen-bonded to histidine 190 (His190) is essential for its functions. For example, the Tyrz-His190 pair provides a proton-coupled electron transfer (PCET) pathway that effectively competes against the back-electron transfer reaction and tunes the redox potential of the phenoxyl radical/phenol redox couple ensuring a high net quantum yield of photoinduced charge separation in PSII. Herein, artificial assemblies mimicking both the structural and redox properties of the Tyrz-His190 pair are described. The bioinspired constructs contain a phenol (Tyrz model) covalently linked to a benzimidazole (His190 model) featuring an intramolecular hydrogen bond which closely emulates the one observed in the natural counterpart. Incorporation of electron-withdrawing groups in the benzimidazole moiety systematically changes the intramolecular hydrogen bond strength and modifies the potential of the phenoxyl radical/phenol redox couple over a range of ~ 250 mV. Infrared spectroelectrochemistry (IRSEC) demonstrates the associated one-electron, one-proton transfer (E1PT) process upon electrochemical oxidation of the phenol. The present contribution provides insight regarding the factors controlling the redox potential of the phenol and highlights strategies for the design of futures constructs capable of transporting protons across longer distances while maintaining a high potential of the phenoxyl radical/phenol redox couple.
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Affiliation(s)
- Emmanuel Odella
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA.
| | - Thomas A Moore
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA
| | - Ana L Moore
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287-1604, USA.
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5
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Davis AB, Ihde MH, Busenlehner AM, Davis DL, Mia R, Panella J, Fronczek FR, Bonizzoni M, Wallace KJ. Structural Features of a Family of Coumarin-Enamine Fluorescent Chemodosimeters for Ion Pairs. Inorg Chem 2021; 60:14238-14252. [PMID: 34470218 DOI: 10.1021/acs.inorgchem.1c01734] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A family of coumarin-enamine chemodosimeters is evaluated for their potential use as fluorescent molecular probes for multiple analytes [cadmium(II), cobalt(II), copper(II), iron(II), nickel(II), lead(II), and zinc(II)], as their chloride and acetate salts. These fluorophores displayed excellent optical spectroscopic modulation when exposed to ion pairs with different Lewis acidic and basic properties in dimethyl sulfoxide (DMSO). The chemodosimeters were designed to undergo excited-state intramolecular proton transfer (ESIPT), which leads to significant Stokes shifts (ca. 225 nm) and lower-energy fluorescence emission (ca. 575 nm). A more basic anion, e.g., acetate, inhibited the ESIPT mechanism by deprotonation of the enol, producing a binding pocket (N^O- chelate) that can coordinate to an appropriate metal ion. Coordination of the metal ions enhances the fluorescent intensity via the chelation-enhanced fluorescence emission mechanism. Subjecting the spectroscopic data to linear discriminant analysis provided insights into the source of these systems' markedly different behavior toward ion pairs, despite the subtle structural differences in the organic framework. These compounds are examples of versatile, low-molecular-weight, dual-channel fluorescent sensors for ion-pair recognition. This study paves the way for using these probes as practical components of a sensing array for different metal ions and their respective anions.
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Affiliation(s)
- Aaron B Davis
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, Mississippi 39406 United States
| | - Michael H Ihde
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, United States
| | - Alie M Busenlehner
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, United States
| | - Dana L Davis
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, Mississippi 39406 United States
| | - Rashid Mia
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, Mississippi 39406 United States
| | - Jessica Panella
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, Mississippi 39406 United States
| | - Frank R Fronczek
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Marco Bonizzoni
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, United States.,Alabama Water Institute, The University of Alabama, Tuscaloosa, Alabama 35487-0206, United States
| | - Karl J Wallace
- Department of Chemistry and Biochemistry, The University of Southern Mississippi, Hattiesburg, Mississippi 39406 United States
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6
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Sengupta S, Khan S, Naath Mongal B, Lewis W, Fleck M, Chattopadhyay SK, Naskar S. Electrocatalytic hydrogen production and carbon dioxide conversion by earth abundant transition metal complexes of the Schiff base ligand: (E)-1-((2-dimethylamino)-propylimino)methyl)naphthalene-2-ol. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Chettri S, Brahman D, Sinha B, Jotani MM, Tiekink ERT. Bis[2-(4,5-diphenyl-1 H-imidazol-2-yl)-4-nitrophenolato]copper(II) dihydrate: crystal structure and Hirshfeld surface analysis. Acta Crystallogr E Crystallogr Commun 2019; 75:1664-1671. [PMID: 31709087 PMCID: PMC6829712 DOI: 10.1107/s2056989019013720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 11/22/2022]
Abstract
The crystal and mol-ecular structures of the title CuII complex, isolated as a dihydrate, [Cu(C21H14N3O3)2]·2H2O, reveals a highly distorted coordination geometry inter-mediate between square-planar and tetra-hedral defined by an N2O2 donor set derived from two mono-anionic bidentate ligands. Furthermore, each six-membered chelate ring adopts an envelope conformation with the Cu atom being the flap. In the crystal, imidazolyl-amine-N-H⋯O(water), water-O-H⋯O(coordinated, nitro and water), phenyl-C-H⋯O(nitro) and π(imidazol-yl)-π(nitro-benzene) [inter-centroid distances = 3.7452 (14) and 3.6647 (13) Å] contacts link the components into a supra-molecular layer lying parallel to (101). The connections between layers forming a three-dimensional architecture are of the types nitro-benzene-C-H⋯O(nitro) and phenyl-C-H⋯π(phen-yl). The distorted coordination geometry for the CuII atom is highlighted in an analysis of the Hirshfeld surface calculated for the metal centre alone. The significance of the inter-molecular contacts is also revealed in a study of the calculated Hirshfeld surfaces; the dominant contacts in the crystal are H⋯H (41.0%), O⋯H/H⋯O (27.1%) and C⋯H/H⋯C (19.6%).
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Affiliation(s)
- Sailesh Chettri
- Department of Chemistry, St. Joseph’s College, Darjeeling 734 104, India
| | - Dhiraj Brahman
- Department of Chemistry, St. Joseph’s College, Darjeeling 734 104, India
| | - Biswajit Sinha
- Department of Chemistry, University of North Bengal, Darjeeling 734 013, India
| | - Mukesh M. Jotani
- Department of Physics, Bhavan’s Sheth R. A. College of Science, Ahmedabad, Gujarat 380 001, India
| | - Edward R. T. Tiekink
- Research Centre for Crystalline Materials, School of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
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8
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Llancalahuen FM, Fuentes JA, Carreño A, Zúñiga C, Páez-Hernández D, Gacitúa M, Polanco R, Preite MD, Arratia-Pérez R, Otero C. New Properties of a Bioinspired Pyridine Benzimidazole Compound as a Novel Differential Staining Agent for Endoplasmic Reticulum and Golgi Apparatus in Fluorescence Live Cell Imaging. Front Chem 2018; 6:345. [PMID: 30211148 PMCID: PMC6123694 DOI: 10.3389/fchem.2018.00345] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/23/2018] [Indexed: 12/16/2022] Open
Abstract
In this study, we explored new properties of the bioinspired pyridine benzimidazole compound B2 (2,4-di-tert-butyl-6-(3H-imidazo[4,5-c]pyridine-2-yl)phenol) regarding its potential use as a differential biomarker. For that, we performed 1D 1HNMR (TOCSY), UV-Vis absorption spectra in different organic solvents, voltammetry profile (including a scan-rate study), and TD-DFT calculations that including NBO analyses, to provide valuable information about B2 structure and luminescence. In our study, we found that the B2 structure is highly stable, where the presence of an intramolecular hydrogen bond (IHB) seems to have a crucial role in the stability of luminescence, and its emission can be assigned as fluorescence. In fact, we found that the relatively large Stokes Shift observed for B2 (around 175 nm) may be attributed to the stability of the B2 geometry and the strength of its IHB. On the other hand, we determined that B2 is biocompatible by cytotoxicity experiments in HeLa cells, an epithelial cell line. Furthermore, in cellular assays we found that B2 could be internalized by passive diffusion in absence of artificial permeabilization at short incubation times (15 min to 30 min). Fluorescence microscopy studies confirmed that B2 accumulates in the endoplasmic reticulum (ER) and Golgi apparatus, two organelles involved in the secretory pathway. Finally, we determined that B2 exhibited no noticeable blinking or bleaching after 1 h of continuous exposure. Thus, B2 provides a biocompatible, rapid, simple, and efficient way to fluorescently label particular organelles, producing similar results to that obtained with other well-established but more complex methods.
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Affiliation(s)
- Felipe M Llancalahuen
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile
| | - Juan A Fuentes
- Laboratorio de Patogénesis y Genética Bacteriana, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Alexander Carreño
- Center of Applied Nanosciences, Universidad Andres Bello, Santiago, Chile.,Fondo Nacional de Ciencia y Tecnología (FONDECYT), Santiago, Chile
| | - César Zúñiga
- Center of Applied Nanosciences, Universidad Andres Bello, Santiago, Chile
| | | | | | - Rubén Polanco
- Centro de Biotecnología Vegeta, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Marcelo D Preite
- Departamento de Química Orgánica, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Carolina Otero
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile
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9
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Syiemlieh I, Kumar A, Kurbah SD, Lal RA. Synthesis, characterization and structure assessment of mononuclear and binuclear low-spin manganese(II) complexes derived from oxaloyldihydrazones, 1,10-phenanthroline and 2,2′-bipyridine. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2018.04.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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10
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Weissman A, Amir D, Elias Y, Pinkas I, Mathias JL, Benisvy L, Salomon A. Bio-inspired Photocatalytic Ruthenium Complexes: Synthesis, Optical Properties, and Solvatochromic Effect. Chemphyschem 2018; 19:220-226. [PMID: 29194896 DOI: 10.1002/cphc.201701061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/27/2017] [Indexed: 11/11/2022]
Abstract
We report the synthesis, characterization, and photo-physical properties of two new rutheniumII -phenol-imidazole complexes. These bio-mimetic complexes have potential as photocatalysts for water splitting. Owing to their multiple phenol-imidazole groups, they have a higher probability of light-induced radical formation than existing complexes. The newly synthesized complexes show improved overlap with the solar spectrum compared to other rutheniumII -phenol-imidazole complexes, and their measured lifetimes are suitable for light-induced radical formation. In addition, we conducted solvatochromic absorption measurements, which elegantly follow Marcus theory, and demonstrate the symmetry differences between the two complexes. The solvatochromic measurements further imply electron localization onto one of the ligands. The new complexes may find applications in photocatalysis, dye-sensitized solar cells, biomedicine, and sensing. Moreover, their multiple chelating units make them promising candidates for light-activated metal organic radical frameworks, i.e. metal-organic frameworks that contain organic radicals activated by light.
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Affiliation(s)
- Adam Weissman
- Department of Chemistry, Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Dan Amir
- Department of Life Sciences, Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Yuval Elias
- Department of Chemistry, Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Iddo Pinkas
- Faculty of Chemistry, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Jenny-Lee Mathias
- Department of Chemistry, Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Laurent Benisvy
- Department of Chemistry, Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
| | - Adi Salomon
- Department of Chemistry, Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan, 5290002, Israel
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11
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Low-spin manganese(II) and high-spin manganese(III) complexes derived from disalicylaldehyde oxaloyldihydrazone: Synthesis, spectral characterization and electrochemical studies. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2017.09.052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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13
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Safaei E, Bahrami H, Wojtczak A, Alavi S, Jagličić Z. Redox potential tuning by redox-inactive anions in copper(II) complexes of non-innocent o-aminophenol-based ligand containing benzoxazole: Learning from nature. Polyhedron 2017. [DOI: 10.1016/j.poly.2016.11.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Huang TH, Yang H, Yang G, Zhu SL, Zhang CL. Synthesis, structural characterization and photoluminescent properties of copper(I) coordination polymers with extended C–H⋯π and CN⋯π interactions. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2016.10.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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15
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Ekanayake DM, Kulesa KM, Singh J, Kpogo KK, Mazumder S, Bernhard Schlegel H, Verani CN. A pentadentate nitrogen-rich copper electrocatalyst for water reduction with pH-dependent molecular mechanisms. Dalton Trans 2017; 46:16812-16820. [DOI: 10.1039/c7dt02711g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A copper catalyst is active towards water reduction with distinctive pH-dependent mechanisms. The CuIII–H− intermediate is bypassed by PCET processes.
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16
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Markle TF, Zhang MT, Santoni MP, Johannissen LO, Hammarström L. Proton-Coupled Electron Transfer in a Series of Ruthenium-Linked Tyrosines with Internal Bases: Evaluation of a Tunneling Model for Experimental Temperature-Dependent Kinetics. J Phys Chem B 2016; 120:9308-21. [DOI: 10.1021/acs.jpcb.6b05885] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Todd F. Markle
- Department of Chemistry − Ångström
Laboratory, Uppsala University, P.O. Box 523, S-75120 Uppsala, Sweden
| | - Ming-Tian Zhang
- Department of Chemistry − Ångström
Laboratory, Uppsala University, P.O. Box 523, S-75120 Uppsala, Sweden
| | - Marie-Pierre Santoni
- Department of Chemistry − Ångström
Laboratory, Uppsala University, P.O. Box 523, S-75120 Uppsala, Sweden
| | - Linus O. Johannissen
- Department of Chemistry − Ångström
Laboratory, Uppsala University, P.O. Box 523, S-75120 Uppsala, Sweden
| | - Leif Hammarström
- Department of Chemistry − Ångström
Laboratory, Uppsala University, P.O. Box 523, S-75120 Uppsala, Sweden
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17
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Eckshtain-Levi M, Lavi R, Yufit DS, Daniel B, Green O, Fleker O, Richman M, Rahimipour S, Gruzman A, Benisvy L. A versatile water-soluble chelating and radical scavenging platform. Chem Commun (Camb) 2016; 52:2350-3. [DOI: 10.1039/c5cc08198j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The reported water-soluble, non-cytotoxic phenol-diamide compound, 1OH, is capable of both, trapping ROS species and chelating Cu(ii)/Fe(iii) ions; thereby inducing a protective effect against ROS induced cell death.
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Affiliation(s)
| | - Ronit Lavi
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
| | | | - Bareket Daniel
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
| | - Omer Green
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
| | - Ohad Fleker
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
| | - Michal Richman
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
| | - Shai Rahimipour
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
| | - Arie Gruzman
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
| | - Laurent Benisvy
- Department of Chemistry
- Bar-Ilan University
- Ramat Gan 52900
- Israel
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18
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Benisvy L, Zats GM, Fleker O, Yufit DS, Orio M, Romanenko G, Ovcharenko V. X-ray structure of a Ni(II)-tri-phenoxyl radical complex. Dalton Trans 2015; 44:17924-6. [PMID: 26427015 DOI: 10.1039/c5dt03131a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The diimino-diphenolato neutral square-planar Ni(ii) complex, NiL2, is readily oxidised with 2 equiv. of Ag[SbF6], to produce an unprecedented octahedral Ni(ii) tris(phenoxyl) radical complex, [Ni(L˙)3][SbF6]2. This study reveals, for the first time, the X-ray structure of a metal-tri-phenoxyl radical complex.
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Affiliation(s)
- Laurent Benisvy
- Department of Chemistry, Bar-Ilan University, Ramat Gan 52900, Israel.
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19
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Parween A, Mandal TK, Guillot R, Naskar S. Acid–base behavior, electrochemical properties and DFT study of redox non-innocent phenol–imidazole ligands and their Cu complexes. Polyhedron 2015. [DOI: 10.1016/j.poly.2015.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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20
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Wilting A, Kügler M, Siewert I. Phenol Based-Ligands with Two AdjacentN,N′,O-Binding Pockets. Z Anorg Allg Chem 2015. [DOI: 10.1002/zaac.201500599] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Ali A, Barman SK, Mukherjee R. Palladium(II) Complex of a Redox-Active Amidophenolate-Based O,N,S,N Ligand: Its Monocation and Dication and Reactivity with PPh3. Inorg Chem 2015; 54:5182-94. [DOI: 10.1021/ic503103e] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Akram Ali
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India
| | - Suman K. Barman
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India
- Department of Chemistry, Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India
| | - Rabindranath Mukherjee
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, India
- Department of Chemistry, Indian Institute of Science Education and Research Kolkata, Mohanpur 741 246, India
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22
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Peng J, Yang HJ, Wei Z, Guo CY. Metal complexes bearing 2-(imidazol-2-yl)phenol ligands: synthesis, characterization and catalytic performance in the fixation of carbon dioxide with epoxides. RSC Adv 2015. [DOI: 10.1039/c5ra08237d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A series of metal complexes bearing 2-(imidazol-2-yl)phenol ligands were synthesized and proven to be efficient catalysts for the fixation of CO2.
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Affiliation(s)
- Jing Peng
- The State Key Laboratory of Power Transmission Equipment & System Security and New Technology
- College of Chemistry and Chemical Engineering
- Chongqing University
- Chongqing 400044
- China
| | - Hai-Jian Yang
- Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education
- Hubei Province
- Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission
- College of Chemistry and Materials Science
- South-Central University for Nationalities
| | - Zidong Wei
- The State Key Laboratory of Power Transmission Equipment & System Security and New Technology
- College of Chemistry and Chemical Engineering
- Chongqing University
- Chongqing 400044
- China
| | - Cun-Yue Guo
- School of Chemistry and Chemical Engineering
- University of Chinese Academy of Sciences
- Beijing
- P.R. China
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23
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Alaji Z, Safaei E, Chiang L, Clarke RM, Mu C, Storr T. A Copper Complex of a Noninnocent Iminophenol-Amidopyridine Hybrid Ligand: Synthesis, Characterization, and Aerobic Alcohol Oxidation. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402687] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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24
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Neidlinger A, Ksenofontov V, Heinze K. Proton-Coupled Electron Transfer in Ferrocenium–Phenolate Radicals. Organometallics 2013. [DOI: 10.1021/om400498h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Andreas Neidlinger
- Institute of Inorganic
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg
10-14, 55128 Mainz, Germany
| | - Vadim Ksenofontov
- Institute of Inorganic
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Staudinger
Weg 9, 55128 Mainz, Germany
| | - Katja Heinze
- Institute of Inorganic
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg
10-14, 55128 Mainz, Germany
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25
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Wen HL, Wen W, Li DD, Liu CB, He M. Hydrothermal syntheses, structures, and properties of the first examples of lanthanide 4-(4,5-diphenyl-1H-imidazol-2-yl)benzote complexes. J COORD CHEM 2013. [DOI: 10.1080/00958972.2013.812204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Hui-Liang Wen
- a State Key Laboratory of Food Science and Technology , Nanchang University , Nanchang , P.R. China
| | - Wen Wen
- a State Key Laboratory of Food Science and Technology , Nanchang University , Nanchang , P.R. China
| | - Dan-Dan Li
- a State Key Laboratory of Food Science and Technology , Nanchang University , Nanchang , P.R. China
| | - Chong-Bo Liu
- b School of Environment and Chemical Engineering , Nanchang Hangkong University , Nanchang , P.R. China
| | - Min He
- a State Key Laboratory of Food Science and Technology , Nanchang University , Nanchang , P.R. China
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26
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Shingai H, Houjou H, Yoshikawa I, Araki K. A Redox-Active, Amphoteric Pyrogallolaldehyde Derivative: Electrochemical Characterization and Schiff Base Formation for Constructing Multifunctional Salphen Complexes. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2013. [DOI: 10.1246/bcsj.20120316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hajime Shingai
- Institute of Industrial Science, The University of Tokyo
| | | | - Isao Yoshikawa
- Institute of Industrial Science, The University of Tokyo
| | - Koji Araki
- Institute of Industrial Science, The University of Tokyo
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27
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Arion VB, Platzer S, Rapta P, Machata P, Breza M, Vegh D, Dunsch L, Telser J, Shova S, Mac Leod TCO, Pombeiro AJL. Marked Stabilization of Redox States and Enhanced Catalytic Activity in Galactose Oxidase Models Based on Transition Metal S-Methylisothiosemicarbazonates with −SR Group in Ortho Position to the Phenolic Oxygen. Inorg Chem 2013; 52:7524-40. [DOI: 10.1021/ic4004966] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vladimir B. Arion
- Institute
of Inorganic Chemistry, University of Vienna, Währinger Strasse
42, A-1090 Vienna, Austria
| | - Sonja Platzer
- Institute
of Inorganic Chemistry, University of Vienna, Währinger Strasse
42, A-1090 Vienna, Austria
| | - Peter Rapta
- Faculty of Chemical and Food Technology, Slovak University of Technology,
Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Peter Machata
- Faculty of Chemical and Food Technology, Slovak University of Technology,
Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Martin Breza
- Faculty of Chemical and Food Technology, Slovak University of Technology,
Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Daniel Vegh
- Faculty of Chemical and Food Technology, Slovak University of Technology,
Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Lothar Dunsch
- Centre of Spectroelectrochemistry,
Leibniz Institute of Solid State and Materials Research Dresden, Helmholtzstrasse
20, D-01069 Dresden, Germany
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt
University, 430 South Michigan Avenue, Chicago, Illinois 60605, United
States
| | - Sergiu Shova
- “Petru Poni”
Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A,
700487 Iasi, Romania
| | - Tatiana C. O. Mac Leod
- Centro de
Quimica Estrutural, Instituto Superior Técnico, Technical University
of Lisbon, Lisbon, Portugal
| | - Armando J. L. Pombeiro
- Centro de
Quimica Estrutural, Instituto Superior Técnico, Technical University
of Lisbon, Lisbon, Portugal
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28
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Franks M, Gadzhieva A, Ghandhi L, Murrell D, Blake AJ, Davies ES, Lewis W, Moro F, McMaster J, Schröder M. Five Coordinate M(II)-Diphenolate [M = Zn(II), Ni(II), and Cu(II)] Schiff Base Complexes Exhibiting Metal- and Ligand-Based Redox Chemistry. Inorg Chem 2013; 52:660-70. [DOI: 10.1021/ic301731w] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Mark Franks
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
| | | | - Laura Ghandhi
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
| | - David Murrell
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
| | | | - E. Stephen Davies
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
| | - William Lewis
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
| | - Fabrizio Moro
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
| | - Jonathan McMaster
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
| | - Martin Schröder
- School of
Chemistry, University of Nottingham, Nottingham
NG7 2RD, U.K
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29
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Mathias JL, Arora H, Lavi R, Vezin H, Yufit D, Orio M, Aliaga-Alcade N, Benisvy L. Redox-switchable tetra-copper assembly of N,N-, N,O-phenolate-phenanthroimidazolate bridging ligands. Dalton Trans 2013; 42:2358-61. [PMID: 23295351 DOI: 10.1039/c2dt32585c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A redox-active dianionic N,O-phenolate-imidazolate/N,N-phenanthroline bridging ligand is used to form unique square-like neutral tetra-Cu(II) assemblies, the structural, magnetic, electronic and redox properties of which are herein described.
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Affiliation(s)
- Jenny-Lee Mathias
- Department of Chemistry, Bar-Ilan University, Ramat Gan, 52 900, Israel
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30
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Butsch K, Günther T, Klein A, Stirnat K, Berkessel A, Neudörfl J. Redox chemistry of copper complexes with various salen type ligands. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2012.08.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Schrauben JN, Cattaneo M, Day TC, Tenderholt AL, Mayer JM. Multiple-site concerted proton-electron transfer reactions of hydrogen-bonded phenols are nonadiabatic and well described by semiclassical Marcus theory. J Am Chem Soc 2012; 134:16635-45. [PMID: 22974135 PMCID: PMC3476473 DOI: 10.1021/ja305668h] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Photo-oxidations of hydrogen-bonded phenols using excited-state polyarenes are described to derive fundamental understanding of multiple-site concerted proton-electron transfer reactions (MS-CPET). Experiments have examined phenol bases having -CPh(2)NH(2), -Py, and -CH(2)Py groups ortho to the phenol hydroxyl group and tert-butyl groups in the 4,6-positions for stability (HOAr-NH(2), HOAr-Py, and HOAr-CH(2)Py, respectively; Py = pyridyl; Ph = phenyl). The photo-oxidations proceed by intramolecular proton transfer from the phenol to the pendent base concerted with electron transfer to the excited polyarene. For comparison, 2,4,6-(t)Bu(3)C(6)H(2)OH, a phenol without a pendent base and tert-butyl groups in the 2,4,6-positions, has also been examined. Many of these bimolecular reactions are fast, with rate constants near the diffusion limit. Combining the photochemical k(CPET) values with those from prior thermal stopped-flow kinetic studies gives data sets for the oxidations of HOAr-NH(2) and HOAr-CH(2)Py that span over 10(7) in k(CPET) and nearly 0.9 eV in driving force (ΔG(o)'). Plots of log(k(CPET)) vs ΔG(o)', including both excited-state anthracenes and ground state aminium radical cations, define a single Marcus parabola in each case. These two data sets are thus well described by semiclassical Marcus theory, providing a strong validation of the use of this theory for MS-CPET. The parabolas give λ(CPET) ≅ 1.15-1.2 eV and H(ab) ≅ 20-30 cm(-1). These experiments represent the most direct measurements of H(ab) for MS-CPET reactions to date. Although rate constants are available only up to the diffusion limit, the parabolas clearly peak well below the adiabatic limit of ca. 6 × 10(12) s(-1). Thus, this is a very clear demonstration that the reactions are nonadiabatic. The nonadiabatic character slows the reactions by a factor of ~45. Results for the oxidation of HOAr-Py, in which the phenol and base are conjugated, and for oxidation of 2,4,6-(t)Bu(3)C(6)H(2)OH, which lacks a base, show that both have substantially lower λ and larger pre-exponential terms. The implications of these results for MS-CPET reactions are discussed.
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Affiliation(s)
| | | | - Thomas C. Day
- Department of Chemistry, University of Washington, Seattle WA 98195
| | | | - James M. Mayer
- Department of Chemistry, University of Washington, Seattle WA 98195
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32
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Chiang L, Kochem A, Jarjayes O, Dunn TJ, Vezin H, Sakaguchi M, Ogura T, Orio M, Shimazaki Y, Thomas F, Storr T. Radical Localization in a Series of Symmetric NiIIComplexes with Oxidized Salen Ligands. Chemistry 2012; 18:14117-27. [DOI: 10.1002/chem.201201410] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Indexed: 11/12/2022]
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33
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Butsch K, Klein A, Nitsche S, Stirnat K, Hawkett JR, McInnes EJL, Bauer M. Generation and characterisation of the phenoxyl-radical containing Cu(II) complex [Cu(triaz)2]+ (triaz- = O,N chelating triazole-phenolate). Dalton Trans 2012; 41:11464-75. [PMID: 22895494 DOI: 10.1039/c2dt31369c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The new copper complex [Cu(triaz)(2)] (Htriaz = 2,4-di-(tert-butyl)-6-(5-chloro-2H-benzo[d][1,2,3]triazol-2-yl)phenol) was investigated in detail by single crystal XRD, EPR-, UV/Vis-absorption-, CV-, and spectroelectrochemistry. The oxidised species [Cu(triaz)(2)](+) was characterised by UV/Vis spectroelectrochemistry and contains a phenoxyl-radical bound to Cu(II). This quite stable species was chemically generated by two different methods: aerial oxidation of a Cu(I) precursor in the presence of Htriaz (and base) or from [Cu(triaz)(2)] by adding a Cu(II) salt (disproportionation). The efficiency for the latter reaction has been studied by UV/Vis spectroscopy, XAS and catalytic test reactions (oxidation of benzyl alcohol).
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Affiliation(s)
- Katharina Butsch
- Universität zu Köln, Department für Chemie, Institut für Anorganische Chemie, Greinstrasse 6, D-50939 Köln, Germany
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34
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Saberikia I, Safaei E, Rafiee M, Cotič P, Bruno G, Rudbari HA. A biologically relevant iron(III) phenoxyl radical complex: A thermodynamic investigation on the structure-radical stability relationship. J Mol Struct 2012. [DOI: 10.1016/j.molstruc.2012.04.084] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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35
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Orio M, Jarjayes O, Baptiste B, Philouze C, Duboc C, Mathias JL, Benisvy L, Thomas F. Geometric and Electronic Structures of Phenoxyl Radicals Hydrogen Bonded to Neutral and Cationic Partners. Chemistry 2012; 18:5416-29. [DOI: 10.1002/chem.201102854] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Indexed: 11/06/2022]
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36
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Wen HL, Wang TT, Liu CB, He M, Wang YX. Hydrothermal syntheses and structures of transition metal 2-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid complexes. J COORD CHEM 2012. [DOI: 10.1080/00958972.2012.657186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Hui-Liang Wen
- a State Key Laboratory of Food Science and Technology, Nanchang University , Nanchang 330047 , People's Republic of China
| | - Tao-Tao Wang
- a State Key Laboratory of Food Science and Technology, Nanchang University , Nanchang 330047 , People's Republic of China
| | - Chong-Bo Liu
- b School of Environment and Chemical Engineering, Nanchang Hangkong University , Nanchang 330063 , People's Republic of China
| | - Min He
- a State Key Laboratory of Food Science and Technology, Nanchang University , Nanchang 330047 , People's Republic of China
| | - Yuan-Xing Wang
- a State Key Laboratory of Food Science and Technology, Nanchang University , Nanchang 330047 , People's Republic of China
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37
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Zats GM, Arora H, Lavi R, Yufit D, Benisvy L. H-bonding and steric effects on the properties of phenolate and phenoxyl radical complexes of Cu(ii). Dalton Trans 2012; 41:47-9. [DOI: 10.1039/c1dt11868d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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38
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Markle TF, Rhile IJ, Mayer JM. Kinetic effects of increased proton transfer distance on proton-coupled oxidations of phenol-amines. J Am Chem Soc 2011; 133:17341-52. [PMID: 21919508 PMCID: PMC3228417 DOI: 10.1021/ja2056853] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To test the effect of varying the proton donor-acceptor distance in proton-coupled electron transfer (PCET) reactions, the oxidation of a bicyclic amino-indanol (2) is compared with that of a closely related phenol with an ortho CPh(2)NH(2) substituent (1). Spectroscopic, structural, thermochemical, and computational studies show that the two amino-phenols are very similar, except that the O···N distance (d(ON)) is >0.1 Å longer in 2 than in 1. The difference in d(ON) is 0.13 ± 0.03 Å from X-ray crystallography and 0.165 Å from DFT calculations. Oxidations of these phenols by outer-sphere oxidants yield distonic radical cations (•)OAr-NH(3)(+) by concerted proton-electron transfer (CPET). Simple tunneling and classical kinetic models both predict that the longer donor-acceptor distance in 2 should lead to slower reactions, by ca. 2 orders of magnitude, as well as larger H/D kinetic isotope effects (KIEs). However, kinetic studies show that the compound with the longer proton-transfer distance, 2, exhibits smaller KIEs and has rate constants that are quite close to those of 1. For example, the oxidation of 2 by the triarylamminium radical cation N(C(6)H(4)OMe)(3)(•+) (3a(+)) occurs at (1.4 ± 0.1) × 10(4) M(-1) s(-1), only a factor of 2 slower than the closely related reaction of 1 with N(C(6)H(4)OMe)(2)(C(6)H(4)Br)(•+) (3b(+)). This difference in rate constants is well accounted for by the slightly different free energies of reaction: ΔG° (2 + 3a(+)) = +0.078 V versus ΔG° (1 + 3b(+)) = +0.04 V. The two phenol-amines do display some subtle kinetic differences: for instance, compound 2 has a shallower dependence of CPET rate constants on driving force (Brønsted α, Δ ln(k)/Δ ln(K(eq))). These results show that the simple tunneling model is not a good predictor of the effect of proton donor-acceptor distance on concerted-electron transfer reactions involving strongly hydrogen-bonded systems. Computational analysis of the observed similarity of the two phenols emphasizes the importance of the highly anharmonic O···H···N potential energy surface and the influence of proton vibrational excited states.
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Affiliation(s)
- Todd F Markle
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
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39
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Wanke R, Benisvy L, Kuznetsov ML, Guedes da Silva MFC, Pombeiro AJL. Persistent Hydrogen-Bonded and Non-Hydrogen-Bonded Phenoxyl Radicals. Chemistry 2011; 17:11882-92. [DOI: 10.1002/chem.201101509] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Indexed: 11/10/2022]
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40
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Uma Maheswari P, Hartl F, Quesada M, Buda F, Lutz M, Spek AL, Gamez P, Reedijk J. Spectro-electrochemical and DFT studies of a planar Cu(II)–phenolate complex active in the aerobic oxidation of primary alcohols. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.03.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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41
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Benisvy L, Wanke R, Guedes da Silva MFC, Pombeiro AJL. A Dianionic Dinickel(II) Complex and Its Oxidised Phenoxyl Radical States. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100232] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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42
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Zats GM, Arora H, Lavi R, Yufit D, Benisvy L. Phenolate and phenoxyl radical complexes of Cu(ii) and Co(iii), bearing a new redox active N,O-phenol-pyrazole ligand. Dalton Trans 2011; 40:10889-96. [DOI: 10.1039/c1dt10615e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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43
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Özalp-Yaman Ş, de Hoog P, Maheswari PU, Casellas H, Golobič A, Kozlevčar B, Gamez P, Reedijk J. Spectroelectrochemical studies of nuclease-active zinc(II) coordination compounds from the ligands Hpyramol and Hpyrimol. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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44
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Di Iulio C, Jones MD, Mahon MF, Apperley DC. Zinc(II) silsesquioxane complexes and their application for the ring-opening polymerization of rac-lactide. Inorg Chem 2010; 49:10232-4. [PMID: 20939505 DOI: 10.1021/ic101809r] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this Communication, we report the unprecedented solid-state structures for a series of zinc(II) silsesquioxane complexes. Initial catalytic data for the ring-opening polymerization of rac-lactide are also presented together with analogous heterogeneous species.
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Affiliation(s)
- Carlo Di Iulio
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
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45
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Mukherjee A, Lloret F, Mukherjee R. Diphenoxido‐Bridged Co
II
and Zn
II
Complexes of Tripodal N
2
O
2
Ligands: Stabilisation of M
II
‐Coordinated Phenoxyl Radical Species. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.200900760] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Atasi Mukherjee
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India, Fax: +91‐512‐2597437
| | - Francesc Lloret
- Departament de Química Inorgànica, Instituto de Ciencia Molecular (ICMOL), Universitat de València, Polígono de la Coma, s/n, 46980 Paterna, València, Spain
| | - Rabindranath Mukherjee
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India, Fax: +91‐512‐2597437
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Özdemir N, Eren B, Dinçer M, Bekdemir Y. Experimental and ab initio computational studies on 4-(1H-benzo[d]imidazol-2-yl)-N,N-dimethylaniline. Mol Phys 2010. [DOI: 10.1080/00268970903476688] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Namık Özdemir
- a Department of Physics, Faculty of Arts and Sciences , Ondokuz Mayıs University , 55139 Kurupelit, Samsun, Turkey
| | - Bilge Eren
- b Department of Chemistry, Faculty of Arts and Sciences , Ondokuz Mayıs University , 55139 Kurupelit, Samsun, Turkey
| | - Muharrem Dinçer
- a Department of Physics, Faculty of Arts and Sciences , Ondokuz Mayıs University , 55139 Kurupelit, Samsun, Turkey
| | - Yunus Bekdemir
- b Department of Chemistry, Faculty of Arts and Sciences , Ondokuz Mayıs University , 55139 Kurupelit, Samsun, Turkey
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Weinberg DR, Hazari N, Labinger JA, Bercaw JE. Iridium(I) and Iridium(III) Complexes Supported by a Diphenolate Imidazolyl-Carbene Ligand. Organometallics 2009. [DOI: 10.1021/om900803r] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David R. Weinberg
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125
| | - Nilay Hazari
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125
| | - Jay A. Labinger
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125
| | - John E. Bercaw
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125
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Rodríguez-Rodríguez C, Sánchez de Groot N, Rimola A, Alvarez-Larena A, Lloveras V, Vidal-Gancedo J, Ventura S, Vendrell J, Sodupe M, González-Duarte P. Design, selection, and characterization of thioflavin-based intercalation compounds with metal chelating properties for application in Alzheimer's disease. J Am Chem Soc 2009; 131:1436-51. [PMID: 19133767 DOI: 10.1021/ja806062g] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metal chelation is considered a rational therapeutic approach for interdicting Alzheimer's amyloid pathogenesis. At present, enhancing the targeting and efficacy of metal-ion chelating agents through ligand design is a main strategy in the development of the next generation of metal chelators. Inspired by the traditional dye Thioflavin-T, we have designed new multifunctional molecules that contain both amyloid binding and metal chelating properties. In silico techniques have enabled us to identify commercial compounds that enclose the designed molecular framework (M1), include potential antioxidant properties, facilitate the formation of iodine-labeled derivatives, and can be permeable through the blood-brain barrier. Iodination reactions of the selected compounds, 2-(2-hydroxyphenyl)benzoxazole (HBX), 2-(2-hydroxyphenyl)benzothiazole (HBT), and 2-(2-aminophenyl)-1H-benzimidazole (BM), have led to the corresponding iodinated derivatives HBXI, HBTI, and BMI, which have been characterized by X-ray diffraction. The chelating properties of the latter compounds toward Cu(II) and Zn(II) have been examined in the solid phase and in solution. The acidity constants of HBXI, HBTI, and BMI and the formation constants of the corresponding ML and ML2 complexes [M = Cu(II), Zn(II)] have been determined by UV-vis pH titrations. The calculated values for the overall formation constants for the ML2 complexes indicate the suitability of the HBXI, HBTI, and BMI ligands for sequestering Cu(II) and Zn(II) metal ions present in freshly prepared solutions of beta-amyloid (Abeta) peptide. This was confirmed by Abeta aggregation studies showing that these compounds are able to arrest the metal-promoted increase in amyloid fibril buildup. The fluorescence features of HBX, HBT, BM, and the corresponding iodinated derivatives, together with fluorescence microscopy studies on two types of pregrown fibrils, have shown that HBX and HBT compounds could behave as potential markers for the presence of amyloid fibrils, whereas HBXI and HBTI may be especially suitable for radioisotopic detection of Abeta deposits. Taken together, the results reported in this work show the potential of new multifunctional thioflavin-based chelating agents as Alzheimer's disease therapeutics.
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Rotthaus O, Jarjayes O, Philouze C, Del Valle CP, Thomas F. One-electron oxidized nickel(II) complexes of bis and tetra(salicylidene) phenylenediamine Schiff bases: from monoradical to interacting Ni(III) ions. Dalton Trans 2009:1792-800. [DOI: 10.1039/b811702k] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Michel F, Hamman S, Philouze C, Del Valle CP, Saint-Aman E, Thomas F. Galactose oxidase models: insights from 19F NMR spectroscopy. Dalton Trans 2008:832-42. [PMID: 19156277 DOI: 10.1039/b813036a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
(19)F labelled tripodal ligands that possess a N(3)O donor set (one phenol, one tertiary amine and either two pyridines or one pyridine and one quinoline) have been synthesized. The fluorine is incorporated either at the phenol O-donor (HL(F) and HL(CF3)) or at the quinoline N-donor (HLq(OMe) and HLq(NO2)). The copper(ii)-phenol complexes (2H)(2+), (1H)(2+), (3H)(2+) and (4H)(2+) as well as the corresponding copper(ii)-phenolate complexes have been characterized. X-Ray diffraction reveals an increase in the oxygen-copper bond distance of more than 0.4 A upon protonation of the phenolate moiety of (4)(+). Protonation is accompanied by an axial to equatorial isomerization of the quinoline group. DFT calculations show that stretching of the Cu-O(phenol) bond, pi-stacking interactions and rotation of the pyridine are key steps in this isomerization process. Protonation, and thus changes in the oxygen-copper bond distance induce either a decrease ((1H)(2+), (2H)(2+)) or an increase ((3H)(2+) and (4H)(2+)) in the copper-fluorine distance that could be monitored by (19)F NMR. In the former case, a broadening of the (19)F NMR signal is observed, whereas a sharpening is observed in the latter case. Temperature dependent (19)F NMR measurements on equimolar mixtures of the phenol and phenolate complexes of (3)(+) and (4)(+) reveal rate constants for proton transfer and/or isomerization of 3000 +/- 100 s(-1) and 2900 +/- 100 s(-1), respectively, at the coalescence temperature. This temperature was found to be strongly affected by the phenol para-substituent as it is 226 K and ca. 330 K for (3)(+) and (4)(+), respectively. A phenoxyl radical species ((3 )(2+)) could be generated and characterized for the first time by (19)F NMR spectroscopy.
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Affiliation(s)
- Fabien Michel
- Département de Chimie Moléculaire, Chimie Inorganique Redox Biomimétique (CIRE), UMR CNRS 5250, Université J. Fourier, B. P. 53, 38041 Grenoble cedex 9, France
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