1
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Mendieta A, Álvarez-Idaboy JR, Ugalde-Saldívar VM, Flores-Álamo M, Armenta A, Ferrer-Sueta G, Gasque L. Role of Imidazole and Chelate Ring Size in Copper Oxidation Catalysts: An Experimental and Theoretical Study. Inorg Chem 2023; 62:16677-16690. [PMID: 37792328 DOI: 10.1021/acs.inorgchem.3c01236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
In this work, the structural, solution, electrochemical, and catalytic properties of the complexes with ligands derived from imidazole and pyridines were studied. A comparative study of five bioinspired copper catalysts with or without coordinated imidazole and with different chelate ring sizes is presented. Catalytic efficiency on the oxidation of 3,5-di-tert-butylcatechol (DTBC) and ortho-aminophenol (OAP) in a MeOH/H2O medium was assessed by means of the Michaelis-Menten model. Catalysts comprising imidazole-containing ligands and/or a six-membered chelate ring proved to be more efficient in both oxidation reactions. Determination of stability constants and electrochemical parameters of the copper complexes supported the explanation of the catalytic behavior. A catalytic cycle similar for both reactions has been proposed. The results of density functional theory (DFT) free energy calculations for all five complexes and both catalytic reactions agree with the experimental results.
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Affiliation(s)
- Alan Mendieta
- Facultad de Química, Universidad Nacional Autónoma de México, Avenida Universidad 3000, CDMX 04510, México
| | - Juan Raúl Álvarez-Idaboy
- Facultad de Química, Universidad Nacional Autónoma de México, Avenida Universidad 3000, CDMX 04510, México
| | - Víctor M Ugalde-Saldívar
- Facultad de Química, Universidad Nacional Autónoma de México, Avenida Universidad 3000, CDMX 04510, México
| | - Marcos Flores-Álamo
- Facultad de Química, Universidad Nacional Autónoma de México, Avenida Universidad 3000, CDMX 04510, México
| | - Alfonso Armenta
- Facultad de Química, Universidad Nacional Autónoma de México, Avenida Universidad 3000, CDMX 04510, México
| | - Gerardo Ferrer-Sueta
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, UY 11400, Uruguay
| | - Laura Gasque
- Facultad de Química, Universidad Nacional Autónoma de México, Avenida Universidad 3000, CDMX 04510, México
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2
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Bouchey C, Shopov DY, Gruen AD, Tolman WB. Mimicking the Cu Active Site of Lytic Polysaccharide Monooxygenase Using Monoanionic Tridentate N-Donor Ligands. ACS OMEGA 2022; 7:35217-35232. [PMID: 36211076 PMCID: PMC9535706 DOI: 10.1021/acsomega.2c04432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
In an effort to prepare small molecule mimics of the active site of lytic polysaccharide monooxygenase (LPMO), three monoanionic tridentate N donor ligands comprising a central deprotonated amide group flanked by two neutral donors were prepared, and their coordination chemistry with Cu(I) and Cu(II) was evaluated. With Cu(I), a dimer formed, which was characterized by X-ray crystallography and NMR spectroscopy. A variety of mononuclear and dinuclear Cu(II) species with a range of auxiliary ligands (MeCN, Cl-, OH-, OAc-, OBz-, CO3 2-) were prepared and characterized by X-ray diffraction and various spectroscopies (UV-vis, EPR). The complexes exhibit structural similarities to the LPMO active site.
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Affiliation(s)
- Caitlin
J. Bouchey
- Department
of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - Dimitar Y. Shopov
- Department
of Chemistry, Washington University in St.
Louis, One Brookings Drive, Campus Box 1134, St.
Louis, Missouri 63130, United States
| | - Aaron D. Gruen
- Department
of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455, United States
| | - William B. Tolman
- Department
of Chemistry, Washington University in St.
Louis, One Brookings Drive, Campus Box 1134, St.
Louis, Missouri 63130, United States
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3
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Chen QC, Fridman N, Tumanskii B, Gross Z. A chromophore-supported structural and functional model of dinuclear copper enzymes, for facilitating mechanism of action studies. Chem Sci 2021; 12:12445-12450. [PMID: 34603675 PMCID: PMC8480325 DOI: 10.1039/d1sc02593g] [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: 05/11/2021] [Accepted: 08/09/2021] [Indexed: 11/25/2022] Open
Abstract
Type III dicopper centres are the heart of the reactive sites of enzymes that catalyze the oxidation of catechols. Numerous synthetic model complexes have been prepared to uncover the fundamental chemistry involved in these processes, but progress is still lagging much behind that for heme enzymes. One reason is that the latter gain very much from the informative spectroscopic features of their porphyrin-based metal-chelating ligand. We now introduce sapphyrin-chelated dicopper complexes and show that they may be isolated in different oxidation states and coordination geometries, with distinctive colors and electronic spectra due to the heme-like ligands. The dicopper(i) complex 1-Cu2 was characterized by 1H and 19F NMR spectroscopy of the metal-chelating sapphyrin, the oxygenated dicopper(ii) complex 1-Cu2O2 by EPR, and crystallographic data was obtained for the tetracopper(ii)-bis-sapphyrin complex [1-Cu2O2]2. This uncovered a non-heme [Cu4(OH)4]4− cluster, held together with the aid of two sapphyrin ligands, with structural features reminiscent of those of catechol oxidase. Biomimetic activity was demonstrated by the 1-Cu2O2 catalyzed aerobic oxidation of catechol to quinone; the sapphyrin ligand aided very much in gaining information about reactive intermediates and the rate-limiting step of the reaction. Di-copper chelation by sapphyrin facilitates reaction mechanism investigations and characterization of reactive intermediates regarding biomimetic catechol oxidation.![]()
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Affiliation(s)
- Qiu-Cheng Chen
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Haifa 32000 Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Haifa 32000 Israel
| | - Boris Tumanskii
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Haifa 32000 Israel
| | - Zeev Gross
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Haifa 32000 Israel
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4
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Koçoğlu S, Hayvalı Z, Ogutcu H. A polydentate ligand based on 2,2’-dipyridylamine unit linked benzo-15-crown-5; alkali and transition metal complexes; photoresponsive ligand; antimicrobial evaluation against pathogenic microorganisms. TRANSIT METAL CHEM 2021. [DOI: 10.1007/s11243-021-00469-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Crespi AF, Sánchez VM, Vega D, Pérez AL, Brondino CD, Linck YG, Hodgkinson P, Rodríguez-Castellón E, Lázaro-Martínez JM. Paramagnetic solid-state NMR assignment and novel chemical conversion of the aldehyde group to dihydrogen ortho ester and hemiacetal moieties in copper(ii)- and cobalt(ii)-pyridinecarboxaldehyde complexes. RSC Adv 2021; 11:20216-20231. [PMID: 35479880 PMCID: PMC9033980 DOI: 10.1039/d1ra02512k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/01/2021] [Indexed: 12/16/2022] Open
Abstract
The complex chemical functionalization of aldehyde moieties in Cu(ii)- and Co(ii)-pyridinecarboxaldehyde complexes was studied. X-ray studies demonstrated that the aldehyde group (RCHO) of the four pyridine molecules is converted to dihydrogen ortho ester (RC(OCH3)(OH)2) and hemiacetal (RCH(OH)(OCH3)) moieties in both 4-pyridinecarboxaldehyde copper and cobalt complexes. In contrast, the aldehyde group is retained when the 3-pyridinecarboxaldehyde ligand is complexed with cobalt. In the different copper complexes, similar paramagnetic 1H resonance lines were obtained in the solid state; however, the connectivity with the carbon structure and the 1H vicinities were done with 2D 1H–13C HETCOR, 1H–1H SQ/DQ and proton spin diffusion (PSD) experiments. The strong paramagnetic effect exerted by the cobalt center prevented the observation of 13C NMR signals and chemical information could only be obtained from X-ray experiments. 2D PSD experiments in the solid state were useful for the proton assignments in both Cu(ii) complexes. The combination of X-ray crystallography experiments with DFT calculations together with the experimental results obtained from EPR and solid-state NMR allowed the assignment of NMR signals in pyridinecarboxaldehyde ligands coordinated with copper ions. In cases where the crystallographic information was not available, as in the case of the 3-pyridinecarboxaldehyde Cu(ii) complex, the combination of these techniques allowed not only the assignment of NMR signals but also the study of the functionalization of the substituent group. The complex chemical functionalization of the aldehyde group was elucidated in copper and cobalt complexes for 4- and 3-pyridinecarboxaldehyde ligands.![]()
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Affiliation(s)
- Ayelén F Crespi
- Universidad de Buenos Aires - CONICET, Facultad de Farmacia y Bioquímica, Instituto de Química y Metabolismo del Fármaco (IQUIMEFA) Ciudad Autónoma de Buenos Aires Argentina
| | - Verónica M Sánchez
- Centro de Simulación Computacional para Aplicaciones Tecnológicas, CSC-CONICET Ciudad Autónoma de Buenos Aires Argentina.,Universidad Nacional de General San Martín San Martín Buenos Aires Argentina
| | - Daniel Vega
- Universidad Nacional de General San Martín San Martín Buenos Aires Argentina.,Comisión Nacional de Energía Atómica San Martín Buenos Aires Argentina
| | - Ana L Pérez
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral - CONICET, Ciudad Universitaria Santa Fe Argentina
| | - Carlos D Brondino
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral - CONICET, Ciudad Universitaria Santa Fe Argentina
| | | | | | | | - Juan M Lázaro-Martínez
- Universidad de Buenos Aires - CONICET, Facultad de Farmacia y Bioquímica, Instituto de Química y Metabolismo del Fármaco (IQUIMEFA) Ciudad Autónoma de Buenos Aires Argentina
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6
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Characterizations of crystalline structure and catalytic activity of zwitterionic imidazole derivatives. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.05.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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7
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Kupietz K, Białek MJ, Białońska A, Szyszko B, Latos-Grażyński L. Organocopper(III) Phenanthriporphyrin-Exocyclic Transformations. Inorg Chem 2019; 58:1451-1461. [PMID: 30600994 DOI: 10.1021/acs.inorgchem.8b02997] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
5,6-Dimethoxyphenanthriporphyrin 1 and 5,6-dioxophenanthriporphyrin 2 act as suitable organometallic ligands for copper(III), adopting trianionic [CCNN] coordination cores. Under oxidizing conditions, in the presence of methanol, copper(III) phenanthriporphyrin 1-Cu undergoes transformation to copper(III) phenanthriporphodimethene with methoxy substituents attached to two trans meso positions. Addition of acids to 1-Cu yields two isomeric copper(III) isophenanthriporphyrins protonated on one of the meso carbon atoms. Protonation of copper(III) 5,6-dioxophenanthriporphyrin 2-Cu yields the aromatic diprotonated complex 2-Cu-H22+. In the presence of HBF4 2-Cu undergoes borylation at the carbonyl oxygen atoms, forming an aromatic exocyclic boron(III) complex.
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Affiliation(s)
- Kamil Kupietz
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
| | - Michał J Białek
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
| | - Agata Białońska
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
| | - Bartosz Szyszko
- Department of Chemistry , University of Wrocław , F. Joliot-Curie 14 , 50-383 Wrocław , Poland
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8
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Das M, Canaj AB, Bertolasi V, Murrie M, Ray D. Strategic synthesis of [Cu 2], [Cu 4] and [Cu 5] complexes: inhibition and triggering of ligand arm hydrolysis and self-aggregation by chosen ancillary bridges. Dalton Trans 2018; 47:17160-17176. [DOI: 10.1039/c8dt03390k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A new family of CuII-based coordination aggregates is synthesized from HL1 with Cu(ClO4)2·6H2O in the absence and presence of a group of carboxylates.
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Affiliation(s)
- Manisha Das
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721302
- India
| | - Angelos B. Canaj
- WestCHEM
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
| | - Valerio Bertolasi
- Dipartimento di ScienzeChimiche e Farmaceutiche
- University of Ferrara
- 44121 Ferrara
- Italy
| | - Mark Murrie
- WestCHEM
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
| | - Debashis Ray
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721302
- India
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9
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X-Ray Crystallographic Analysis, EPR Studies, and Computational Calculations of a Cu(II) Tetramic Acid Complex. Bioinorg Chem Appl 2017; 2017:7895023. [PMID: 28316540 PMCID: PMC5337788 DOI: 10.1155/2017/7895023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/20/2016] [Accepted: 12/25/2016] [Indexed: 11/26/2022] Open
Abstract
In this work we present a structural and spectroscopic analysis of a copper(II) N-acetyl-5-arylidene tetramic acid by using both experimental and computational techniques. The crystal structure of the Cu(II) complex was determined by single crystal X-ray diffraction and shows that the copper ion lies on a centre of symmetry, with each ligand ion coordinated to two copper ions, forming a 2D sheet. Moreover, the EPR spectroscopic properties of the Cu(II) tetramic acid complex were also explored and discussed. Finally, a computational approach was performed in order to obtain a detailed and precise insight of product structures and properties. It is hoped that this study can enrich the field of functional supramolecular systems, giving place to the formation of coordination-driven self-assembly architectures.
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10
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Reger DL, Pascui AE, Foley EA, Smith MD, Jezierska J, Wojciechowska A, Stoian SA, Ozarowski A. Dinuclear Metallacycles with Single M–X–M Bridges (X = Cl–, Br–; M = Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II)): Strong Antiferromagnetic Superexchange Interactions. Inorg Chem 2017; 56:2884-2901. [PMID: 28218526 DOI: 10.1021/acs.inorgchem.6b02933] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel L. Reger
- Department of Chemistry
and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Andrea E. Pascui
- Department of Chemistry
and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Elizabeth A. Foley
- Department of Chemistry
and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Mark D. Smith
- Department of Chemistry
and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Julia Jezierska
- Faculty of Chemistry, University of Wrocław, 50-383 Wrocław, Poland
| | | | - Sebastian A. Stoian
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
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11
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Ferre FT, Resende JA, Schultz J, Mangrich AS, Faria RB, Rocha AB, Scarpellini M. Catalytic promiscuity of mononuclear copper(II) complexes in mild conditions: Catechol and cyclohexane oxidations. Polyhedron 2017. [DOI: 10.1016/j.poly.2016.11.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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12
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Banerjee K, Basu S, Das S, Sinha A, Biswas MK, Choudhuri SK. Induction of intrinsic and extrinsic apoptosis through oxidative stress in drug-resistant cancer by a newly synthesized Schiff base copper chelate. Free Radic Res 2016; 50:426-46. [PMID: 26733073 DOI: 10.3109/10715762.2015.1136062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Multidrug resistance (MDR) in cancer represents a variety of strategies employed by tumor cells to evade the beneficial cytotoxic effects of structurally different anticancer drugs and thus confers impediments to the successful treatment of cancers. Efflux of drugs by MDR protein-1, functional P-glycoprotein and elevated level of reduced glutathione confer resistance to cell death or apoptosis and thus provide a possible therapeutic target for overcoming MDR in cancer. Previously, we reported that a Schiff base ligand, potassium-N-(2-hydroxy 3-methoxy-benzaldehyde)-alaninate (PHMBA) overcomes MDR in both in vivo and in vitro by targeting intrinsic apoptotic/necrotic pathway through induction of reactive oxygen species (ROS). The present study describes the synthesis and spectroscopic characterization of a copper chelate of Schiff base, viz., copper (II)-N-(2-hydroxy-3-methoxy-benzaldehyde)-alaninate (CuPHMBA) and the underlying mechanism of cell death induced by CuPHMBA in vitro. CuPHMBA kills both the drug-resistant and sensitive cell types irrespective of their drug resistance phenotype. The cell death induced by CuPHMBA follows apoptotic pathway and moreover, the cell death is associated with intrinsic mitochondrial and extrinsic receptor-mediated pathways. Oxidative stress plays a pivotal role in the process as proved by the fact that antioxidant enzyme; polyethylene glycol conjugated-catalase completely blocked CuPHMBA-induced ROS generation and abrogated cell death. To summarize, the present work provides a compelling rationale for the future clinical use of CuPHMBA, a redox active copper chelate in the treatment of cancer patients, irrespective of their drug-resistance status.
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Affiliation(s)
- Kaushik Banerjee
- a Department of In Vitro Carcinogenesis and Cellular Chemotherapy , Chittaranjan National Cancer Institute , Kolkata , West Bengal , India
| | - Soumya Basu
- a Department of In Vitro Carcinogenesis and Cellular Chemotherapy , Chittaranjan National Cancer Institute , Kolkata , West Bengal , India
| | - Satyajit Das
- a Department of In Vitro Carcinogenesis and Cellular Chemotherapy , Chittaranjan National Cancer Institute , Kolkata , West Bengal , India
| | - Abhinaba Sinha
- a Department of In Vitro Carcinogenesis and Cellular Chemotherapy , Chittaranjan National Cancer Institute , Kolkata , West Bengal , India
| | - Manas Kumar Biswas
- b Department of Chemistry , Ramakrishna Mission Residential College , Kolkata , West Bengal , India
| | - Soumitra Kumar Choudhuri
- a Department of In Vitro Carcinogenesis and Cellular Chemotherapy , Chittaranjan National Cancer Institute , Kolkata , West Bengal , India
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13
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Libardo MDJ, Gorbatyuk VY, Angeles-Boza AM. Central Role of the Copper-Binding Motif in the Complex Mechanism of Action of Ixosin: Enhancing Oxidative Damage and Promoting Synergy with Ixosin B. ACS Infect Dis 2016; 2:71-81. [PMID: 27622949 DOI: 10.1021/acsinfecdis.5b00140] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ticks transmit multiple pathogens to different hosts without compromising their health. Their ability to evade microbial infections is largely a result of their effective innate immune response including various antimicrobial peptides. Therefore, a deep understanding of how ticks (and other arthropod vectors) control microbial loads could lead to the design of broad-spectrum antimicrobial agents. In this paper we study the role of the amino-terminal copper and nickel (ATCUN)-binding sequence in the peptide ixosin, isolated from the salivary glands of the hard tick Ixodes sinensis. Our results indicate that the ATCUN motif is not essential to the potency of ixosin, but is indispensable to its oxidative mechanism of action. Specifically, the ATCUN motif promotes dioxygen- and copper-dependent lipid (per)oxidation of bacterial membranes in a temporal fashion coinciding with the onset of bacterial death. Microscopy and studies on model membranes indicate that the oxidized phospholipids are utilized as potential targets of ixosin B (another tick salivary gland peptide) involving its delocalization to the bacterial membrane, thus resulting in a synergistic effect. Our proposed mechanism of action highlights the centrality of the ATCUN motif to ixosin's mechanism of action and demonstrates a novel way in which (tick) antimicrobial peptides (AMPs) utilize metal ions in its activity. This study suggests that ticks employ a variety of effectors to generate an amplified immune response, possibly justifying its vector competence.
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Affiliation(s)
- M. Daben J. Libardo
- Department of Chemistry, University of Connecticut, Unit 3060, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Vitaliy Y. Gorbatyuk
- Department of Chemistry, University of Connecticut, Unit 3060, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
- Biotechnology and Bioservices Center, University of Connecticut, Unit 3149, 91 North Eagleville Road, Storrs, Connecticut 06269, United States
| | - Alfredo M. Angeles-Boza
- Department of Chemistry, University of Connecticut, Unit 3060, 55 North Eagleville Road, Storrs, Connecticut 06269, United States
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14
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Reger DL, Pascui AE, Smith MD, Jezierska J, Ozarowski A. Syntheses, Structural, Magnetic, and Electron Paramagnetic Resonance Studies of Monobridged Cyanide and Azide Dinuclear Copper(II) Complexes: Antiferromagnetic Superexchange Interactions. Inorg Chem 2015; 54:1487-500. [PMID: 25602445 DOI: 10.1021/ic502485p] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Daniel L. Reger
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Andrea E. Pascui
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Mark D. Smith
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Julia Jezierska
- Faculty
of Chemistry, University of Wrocław 50-383 Wrocław, Poland
| | - Andrew Ozarowski
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
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15
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Pait M, Shatruk M, Lengyel J, Gómez-Coca S, Bauzá A, Frontera A, Bertolasi V, Ray D. Two types of nitrito support for μ4-oxido-bridged [Cu4] complexes: synthesis, crystal structures, magnetic properties and DFT analysis. Dalton Trans 2015; 44:6107-17. [DOI: 10.1039/c4dt03224a] [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]
Abstract
In situ generated NO2− and externally added NO2− and AcO− ions have been utilized for the isolation of μ4-oxido-bridged Cu4 aggregates showing magnetic coupling which can be rationalized by DFT calculations.
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Affiliation(s)
- Moumita Pait
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721 302
- India
| | - Michael Shatruk
- Department of Chemistry & Biochemistry
- Florida State University
- Tallahassee
- USA
| | - Jeff Lengyel
- Department of Chemistry & Biochemistry
- Florida State University
- Tallahassee
- USA
| | - Silvia Gómez-Coca
- Departament de Química Inorganica and Institut de Recerca de Química Teórica i Computacional
- Universitat de Barcelona
- E-08028 Barcelona
- Spain
| | - Antonio Bauzá
- Departament de Química
- Universitat de les Illes Balears
- 07122 Palma
- Spain
| | - Antonio Frontera
- Departament de Química
- Universitat de les Illes Balears
- 07122 Palma
- Spain
| | - Valerio Bertolasi
- Dipartimento di Chimica e Centro di Strutturistica Diffrattometica
- Università diFerrara
- 44100 Ferrara
- Italy
| | - Debashis Ray
- Department of Chemistry
- Indian Institute of Technology
- Kharagpur 721 302
- India
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16
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Adhikari S, Banerjee A, Nandi S, Fondo M, Sanmartín-Matalobos J, Das D. Structure, magnetism and catecholase activity of the first dicopper(ii) complex having a single μ-alkoxo bridge. RSC Adv 2015. [DOI: 10.1039/c4ra14603d] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Pyridine-2,6-dimethanol shows a neutral, monoanionic and dianionic coordination behaviour with two different coordination modes viz. tridentate and bidentate towards Cu(ii), leading to three different geometric environments around Cu(ii) centers.
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Affiliation(s)
| | - Arnab Banerjee
- Department of Chemistry
- The University of Burdwan
- Burdwan
- India
| | - Sandip Nandi
- Department of Chemistry
- The University of Burdwan
- Burdwan
- India
| | - Matilde Fondo
- Departamento de Química Inorgánica
- Facultade de Química
- Santiago de Compostela
- Spain
| | | | - Debasis Das
- Department of Chemistry
- The University of Burdwan
- Burdwan
- India
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17
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Shabana AA, Butler IS, Gilson DF, Jean-Claude BJ, Mouhri ZS, Mostafa MM, Mostafa SI. Synthesis, characterization, anticancer activity and DNA interaction studies of new 2-aminobenzothiazole complexes; crystal structure and DFT calculations of [Ag(Habt)2]ClO4. Inorganica Chim Acta 2014. [DOI: 10.1016/j.ica.2014.09.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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18
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Cheng Q, Zhou H, Pan Z, Liao G, Xu Z. Synthesis, structure and magnetic properties of four unexpected di- and tetranuclear Robson-type macrocyclic complexes. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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19
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Reger DL, Pascui AE, Foley EA, Smith MD, Jezierska J, Ozarowski A. Dinuclear Metallacycles with Single M–O(H)–M Bridges [M = Fe(II), Co(II), Ni(II), Cu(II)]: Effects of Large Bridging Angles on Structure and Antiferromagnetic Superexchange Interactions. Inorg Chem 2014; 53:1975-88. [DOI: 10.1021/ic4017905] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel L. Reger
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Andrea E. Pascui
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Elizabeth A. Foley
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Mark D. Smith
- Department
of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Julia Jezierska
- Faculty
of Chemistry, University of Wrocław, 50-383 Wrocław, Poland
| | - Andrew Ozarowski
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
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20
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Nagaj J, Stokowa-Sołtys K, Kurowska E, Frączyk T, Jeżowska-Bojczuk M, Bal W. Revised Coordination Model and Stability Constants of Cu(II) Complexes of Tris Buffer. Inorg Chem 2013; 52:13927-33. [DOI: 10.1021/ic401451s] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Justyna Nagaj
- Faculty
of Chemistry, University of Wroclaw, Wroclaw, Poland
| | | | - Ewa Kurowska
- Institute of Biochemistry and Biophysics, Polish Academy
of Sciences, Warsaw, Poland
| | - Tomasz Frączyk
- Institute of Biochemistry and Biophysics, Polish Academy
of Sciences, Warsaw, Poland
| | | | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy
of Sciences, Warsaw, Poland
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21
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Reger DL, Pascui AE, Pellechia PJ, Ozarowski A. NMR Investigations of Dinuclear, Single-Anion Bridged Copper(II) Metallacycles: Structure and Antiferromagnetic Behavior in Solution. Inorg Chem 2013; 52:12741-8. [DOI: 10.1021/ic402016m] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Daniel L. Reger
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Andrea E. Pascui
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Perry J. Pellechia
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Andrew Ozarowski
- National
High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
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22
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Biswas A, Das LK, Drew MGB, Diaz C, Ghosh A. Insertion of a hydroxido bridge into a diphenoxido dinuclear copper(II) complex: drastic change of the magnetic property from strong antiferromagnetic to ferromagnetic and enhancement in the catecholase activity. Inorg Chem 2012; 51:10111-21. [PMID: 22963285 DOI: 10.1021/ic300319s] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A diphenoxido-bridged dinuclear copper(II) complex, [Cu(2)L(2)(ClO(4))(2)] (1), has been synthesized using a tridentate reduced Schiff base ligand, 2-[[2-(diethylamino)ethylamino]methyl]phenol (HL). The addition of triethylamine to the methanolic solution of this complex produced a novel triple bridged (double phenoxido and single hydroxido) dinuclear copper(II) complex, [Cu(2)L(2)(OH)]ClO(4) (2). Both complexes 1 and 2 were characterized by X-ray structural analyses, variable-temperature magnetic susceptibility measurements, and spectroscopic methods. In 1, the two phenoxido bridges are equatorial-equatorial and the species shows strong antiferromagnetic coupling with J = -615.6(6.1) cm(-1). The inclusion of the equatorial-equatorial hydroxido bridge in 2 changes the Cu···Cu distance from 3.018 Å (avg.) to 2.798 Å (avg.), the positions of the phenoxido bridges to axial-equatorial, and the magnetic coupling to ferromagnetic with J = 50.1(1.4) cm(-1). Using 3,5-di-tert-butylcatechol as the substrate, the catecholase activity of the complexes has been studied in a methanol solution; compound 2 shows higher catecholase activity (k(cat) = 233.4 h(-1)) than compound 1 (k(cat) = 93.6 h(-1)). Both complexes generate identical species in solution, and they are interconvertible simply by changing the pH of their solutions. The higher catecholase activity of 2 seems to be due to the presence of the OH group, which increases the pH of its solution.
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Affiliation(s)
- Apurba Biswas
- Department of Chemistry, University College of Science, University of Calcutta, 92 APC Road, Kolkata 700 009, India
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23
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Reger DL, Pascui AE, Smith MD, Jezierska J, Ozarowski A. Halide and Hydroxide Linearly Bridged Bimetallic Copper(II) Complexes: Trends in Strong Antiferromagnetic Superexchange Interactions. Inorg Chem 2012; 51:7966-8. [DOI: 10.1021/ic301321r] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel L. Reger
- Department of Chemistry and
Biochemistry, University of South Carolina, Columbia, South Carolina
29208, United States
| | - Andrea E. Pascui
- Department of Chemistry and
Biochemistry, University of South Carolina, Columbia, South Carolina
29208, United States
| | - Mark D. Smith
- Department of Chemistry and
Biochemistry, University of South Carolina, Columbia, South Carolina
29208, United States
| | - Julia Jezierska
- Faculty
of Chemistry, University
of Wrocław, 50−383 Wrocław, Poland
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory,
Florida State University, Tallahassee, Florida 32310, United States
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24
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Tjioe L, Joshi T, Forsyth CM, Moubaraki B, Murray KS, Brugger J, Graham B, Spiccia L. Phosphodiester Cleavage Properties of Copper(II) Complexes of 1,4,7-Triazacyclononane Ligands Bearing Single Alkyl Guanidine Pendants. Inorg Chem 2011; 51:939-53. [DOI: 10.1021/ic2019814] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Linda Tjioe
- School of Chemistry, Monash University, Vic 3800, Australia
| | - Tanmaya Joshi
- School of Chemistry, Monash University, Vic 3800, Australia
| | | | | | | | - Joël Brugger
- School of Earth and Environmental
Sciences, Centre of Tectonics, Resources and Exploration (TRaX), The University of Adelaide, North Terrace, SA 5005,
Australia
- Department of Mineralogy, South Australian Museum, Adelaide, SA 5000, Australia
| | - Bim Graham
- Medicinal Chemistry and Drug
Action, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Vic 3052, Australia
| | - Leone Spiccia
- School of Chemistry, Monash University, Vic 3800, Australia
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25
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Das O, Zangrando E, Paine TK. Reactivity of nickel(II) and copper(II) complexes of a β-aminohydrazone ligand with pyridine-2-aldehyde: macrocyclization vs unprecedented pyrazole ring synthesis via C-C bond-forming reaction. Inorg Chem 2011; 50:8012-9. [PMID: 21805958 DOI: 10.1021/ic200261j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis and characterization of a mononuclear nickel(II) complex [Ni(L(2))](ClO(4))(2) (1) and an analogous mononuclear copper(II) complex [Cu(L(2))](ClO(4))(2) (2) of a 15-membered azamacrocycle (L(2) = 3-(2-pyridyl)-6,8,8,13,13,15-hexamethyl-1,2,4,5,9,12-hexaazacyclopentadeca-5,15-diene) are reported. The macrocyclic ligand is formed during the reaction of 4,4,9,9-tetramethyl-5,8-diazadodecane-2,11-dione dihydrazone (L(1)) with pyridine-2-aldehyde (PyCHO) templated by metal ions. The X-ray crystal structure of 1 exhibits a distorted square-pyramidal coordination geometry, where the metal ion sits in the macrocyclic cavity and the pendant pyridine group of L(2) occupies the axial position. While 1 is stable in the presence of an excess of PyCHO, 2 reacts further with copper(II) salt and PyCHO to form a mononuclear copper(I) complex, [Cu(H(2)L(3))](ClO(4))(3) (3). The structure of the complex cation of 3 reveals a distorted tetrahedral coordination geometry at the copper center with a pseudo 2-fold screw axis. A two-dimensional (2D) polymeric copper(II) complex, {[Cu(2)(L(4))(2)](ClO(4))(2)}(n) (4) is obtained by reacting complex 2 (or [Ni(L(1))](ClO(4))(2)) with copper(II) perchlorate and pyridine-2-aldehyde in a methanol-water solvent mixture. Complex 4 is also obtained by treating 3 with copper(II) perchlorate and pyridine-2-aldehyde in the presence of a base. The X-ray structural analysis of 4 confirms the formation of a pyrazolate bridged dimeric copper(II) complex. The extended structure in the solid state of 4 revealed the formation of a 2D coordination polymer with the dimeric core as the repeating unit. The ligand (HL(4)) in 4 is a 3,4,5-trisubstituted pyrazole ring formed in situ via C-C bond formation and represents an unprecedented transformation reaction.
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Affiliation(s)
- Oindrila Das
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
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26
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Neuman NI, Perec M, González PJ, Passeggi MCG, Rizzi AC, Brondino CD. Single Crystal EPR Study of the Dinuclear Cu(II) Complex [Cu(tda)(phen)]2·H2tda (tda = Thiodiacetate, phen = Phenanthroline): Influence of Weak Interdimeric Magnetic Interactions. J Phys Chem A 2010; 114:13069-75. [DOI: 10.1021/jp108736p] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nicolás I. Neuman
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Paraje El Pozo, S3000ZAA Santa Fe, Argentina, Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, INQUIMAE, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina, Departamento da Quimica, Requimte/CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica,
| | - Mireille Perec
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Paraje El Pozo, S3000ZAA Santa Fe, Argentina, Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, INQUIMAE, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina, Departamento da Quimica, Requimte/CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica,
| | - Pablo J. González
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Paraje El Pozo, S3000ZAA Santa Fe, Argentina, Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, INQUIMAE, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina, Departamento da Quimica, Requimte/CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica,
| | - Mario C. G. Passeggi
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Paraje El Pozo, S3000ZAA Santa Fe, Argentina, Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, INQUIMAE, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina, Departamento da Quimica, Requimte/CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica,
| | - Alberto C. Rizzi
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Paraje El Pozo, S3000ZAA Santa Fe, Argentina, Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, INQUIMAE, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina, Departamento da Quimica, Requimte/CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica,
| | - Carlos D. Brondino
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Paraje El Pozo, S3000ZAA Santa Fe, Argentina, Departamento de Química Inorgánica Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, INQUIMAE, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428, Buenos Aires, Argentina, Departamento da Quimica, Requimte/CQFB, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica,
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27
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Datta A, Chuang NT, Liao FX, Hu CH, Huang WY, Huang JH, Das K, Gamez P, Costa JS. A Dissymmetric, Singly Phenoxido-Bridged Cu∥ Dinuclear Coordination Compound: Synthesis, Characterisation, Magnetic and Computational Study. JOURNAL OF CHEMICAL RESEARCH 2010. [DOI: 10.3184/030823410x12886325735063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A singly phenoxido-bridged dinuclear Cu∥ complex, [Cu2(L)2(SCN)2(H2O)], has been obtained from a Schiff-base ligand (2-[{[2-(dimethylamino)ethyl]imino}methyl]-6-methoxyphenol), generated by condensation of o-vanillin with N,N-dimethylethane-1,2-diamine. The Cu(II) complex has been fully characterised by analytical, spectroscopic, magnetic susceptibility and EPR measurements and DFT calculations, as well as single-crystal X-ray diffraction analysis. It consists of two geometrically distinct square-pyramidal and octahedral copper(II) centres, exhibiting N2O3 and N4O2 donor sets. In the dimeric unit, the copper atoms are connected by a μ2-phenolato oxygen atom, belonging to one bridging Schiff-base ligand. Variable-temperature magnetic susceptibility measurements indicate strong antiferromagnetic exchange interactions between the Cu(II) centres, with a 2 J value of −89(1) cm−1.
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Affiliation(s)
- Amitabha Datta
- Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
| | - Nien-Tsu Chuang
- Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
| | - Fu-Xing Liao
- Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
| | - Ching-Han Hu
- Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
| | - Wen-Yen Huang
- Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
| | - Jui-Hsien Huang
- Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
| | - Kuheli Das
- Department of Chemistry, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan
| | - Patrick Gamez
- Leiden University, Leiden Institute of Chemistry, PO Box 9502, 2300 RA Leiden, The Netherlands
| | - José Sánchez Costa
- Departament de Química Inorgànica, Universitat de Barcelona, Diagonal 647, 08028, Barcelona, Spain
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28
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Halime Z, Kieber-Emmons MT, Qayyum MF, Mondal B, Gandhi T, Puiu SC, Chufán EE, Sarjeant AAN, Hodgson KO, Hedman B, Solomon EI, Karlin KD. Heme-copper-dioxygen complexes: toward understanding ligand-environmental effects on the coordination geometry, electronic structure, and reactivity. Inorg Chem 2010; 49:3629-45. [PMID: 20380465 PMCID: PMC2893725 DOI: 10.1021/ic9020993] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nature of the ligand is an important aspect of controlling the structure and reactivity in coordination chemistry. In connection with our study of heme-copper-oxygen reactivity relevant to cytochrome c oxidase dioxygen-reduction chemistry, we compare the molecular and electronic structures of two high-spin heme-peroxo-copper [Fe(III)O(2)(2-)Cu(II)](+) complexes containing N(4) tetradentate (1) or N(3) tridentate (2) copper ligands. Combining previously reported and new resonance Raman and EXAFS data coupled to density functional theory calculations, we report a geometric structure and more complete electronic description of the high-spin heme-peroxo-copper complexes 1 and 2, which establish mu-(O(2)(2-)) side-on to the Fe(III) and end-on to Cu(II) (mu-eta(2):eta(1)) binding for the complex 1 but side-on/side-on (mu-eta(2):eta(2)) mu-peroxo coordination for the complex 2. We also compare and summarize the differences and similarities of these two complexes in their reactivity toward CO, PPh(3), acid, and phenols. The comparison of a new X-ray structure of mu-oxo complex 2a with the previously reported 1a X-ray structure, two thermal decomposition products respectively of 2 and 1, reveals a considerable difference in the Fe-O-Cu angle between the two mu-oxo complexes ( angleFe-O-Cu = 178.2 degrees in 1a and angleFe-O-Cu = 149.5 degrees in 2a). The reaction of 2 with 1 equiv of an exogenous nitrogen-donor axial base leads to the formation of a distinctive low-temperature-stable, low-spin heme-dioxygen-copper complex (2b), but under the same conditions, the addition of an axial base to 1 leads to the dissociation of the heme-peroxo-copper assembly and the release of O(2). 2b reacts with phenols performing H-atom (e(-) + H(+)) abstraction resulting in O-O bond cleavage and the formation of high-valent ferryl [Fe(IV)=O] complex (2c). The nature of 2c was confirmed by a comparison of its spectroscopic features and reactivity with those of an independently prepared ferryl complex. The phenoxyl radical generated by the H-atom abstraction was either (1) directly detected by electron paramagnetic resonance spectroscopy using phenols that produce stable radicals or (2) indirectly detected by the coupling product of two phenoxyl radicals.
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Affiliation(s)
- Zakaria Halime
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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29
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Kharadi GJ, Patel KD. Novel copper(II) heterochelate: synthesis, structural features and fluorescence studies. Appl Organomet Chem 2010. [DOI: 10.1002/aoc.1652] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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30
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Copper(II) complex with tridentate N donor ligand: Synthesis, crystal structure, reactivity and DNA binding study. Polyhedron 2010. [DOI: 10.1016/j.poly.2010.01.022] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Karmakar S, Das O, Ghosh S, Zangrando E, Johann M, Rentschler E, Weyhermüller T, Khanra S, Kanti Paine T. Hexanuclear copper(ii) cage with {Cu3O⋯H⋯OCu3} core supported by a dicompartmental oxime ligand with m-xylyl spacer: synthesis, molecular structure and magnetic studies. Dalton Trans 2010; 39:10920-7. [DOI: 10.1039/c0dt00951b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Núñez C, Bastida R, Macías A, Valencia L, Neuman NI, Rizzi AC, Brondino CD, González PJ, Capelo JL, Lodeiro C. Structural, MALDI-TOF-MS, Magnetic and Spectroscopic Studies of New Dinuclear Copper(ii), Cobalt(ii) and Zinc(ii) Complexes Containing a Biomimicking μ-OH bridge. Dalton Trans 2010; 39:11654-63. [DOI: 10.1039/c0dt00692k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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33
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Siluvai GS, Murthy NN. X-ray structure and spectroscopic characterization of doubly-bridged binuclear copper(II) complexes in symmetric and asymmetric coordination environments. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Refat MS, El-Deen IM, Anwer ZM, El-Ghol S. Spectroscopic studies and biological evaluation of some transition metal complexes of Schiff-base ligands derived from 5-arylazo-salicylaldehyde and thiosemicarbazide. J COORD CHEM 2009. [DOI: 10.1080/00958970802684205] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Moamen S. Refat
- a Department of Chemistry , Faculty of Science–Port Said, Suez Canal University , Port Said, Egypt
- b Department of Chemistry, Faculty of Science–Taif , Taif University , Taif 888, King Saudi Arabia
| | - Ibrahim M. El-Deen
- a Department of Chemistry , Faculty of Science–Port Said, Suez Canal University , Port Said, Egypt
| | - Zeinab M. Anwer
- c Department of Chemistry, Faculty of Science–Ismalia , Suez Canal University , Ismalia, Egypt
| | - Samir El-Ghol
- a Department of Chemistry , Faculty of Science–Port Said, Suez Canal University , Port Said, Egypt
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35
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Budzisz E, Miernicka M, Lorenz IP, Mayer P, Krajewska U, Rozalski M. Synthesis and X-ray structure of platinum(II), palladium(II) and copper(II) complexes with pyridine–pyrazole ligands: Influence of ligands’ structure on cytotoxic activity. Polyhedron 2009. [DOI: 10.1016/j.poly.2008.12.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Sarkar S, Dhara PK, Nethaji M, Chattopadhyay P. Copper(II) complexes of tridentate SNO ligands: synthesis, characterization and crystal structure. J COORD CHEM 2009. [DOI: 10.1080/00958970802314951] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Sandipan Sarkar
- a Department of Chemistry , The University of Burdwan , Golapbag, Burdwan-713104, India
| | - Pulak K. Dhara
- a Department of Chemistry , The University of Burdwan , Golapbag, Burdwan-713104, India
| | - M. Nethaji
- b Department of Inorganic and Physical Chemistry , IISc., Bangalore–560012, India
| | - Pabitra Chattopadhyay
- a Department of Chemistry , The University of Burdwan , Golapbag, Burdwan-713104, India
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37
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Mathrubootham V, Addison AW, Holman KT, Sinn E, Thompson LK. A novel copper(II) complex of a tripodal ligand with phenolate-phenol interligand, intramolecular hydrogen bonding. Dalton Trans 2009:8111-6. [DOI: 10.1039/b910188h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Chatterjee PB, Mandal D, Audhya A, Choi KY, Endo A, Chaudhury M. Reporting a New Class of Divanadium(V) Compounds Connected by an Unsupported Hydroxo Bridge. Inorg Chem 2008; 47:3709-18. [DOI: 10.1021/ic702286h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pabitra Baran Chatterjee
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India, Department of Chemistry Education, Kongju National University, Kongju 314-701, South Korea, and Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Debdas Mandal
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India, Department of Chemistry Education, Kongju National University, Kongju 314-701, South Korea, and Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Anandalok Audhya
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India, Department of Chemistry Education, Kongju National University, Kongju 314-701, South Korea, and Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Ki-Young Choi
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India, Department of Chemistry Education, Kongju National University, Kongju 314-701, South Korea, and Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Akira Endo
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India, Department of Chemistry Education, Kongju National University, Kongju 314-701, South Korea, and Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Muktimoy Chaudhury
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India, Department of Chemistry Education, Kongju National University, Kongju 314-701, South Korea, and Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan
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39
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Mijangos E, Reedijk J, Gasque L. Copper(ii) complexes of a polydentate imidazole-based ligand. pH effect on magnetic coupling and catecholase activity. Dalton Trans 2008:1857-63. [PMID: 18369492 DOI: 10.1039/b714283h] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A potentially dodecadentate N8O4-donor ligand obtained from 2,2'-biimidazole and l-valine and its tetranuclear Cu(ii) complexes in different degrees of protonation were characterized by chemical and spectroscopic methods. The extensive solution studies performed reveal that the rise in pH media leads successively to the formation of imidazolato (pKa(1) and pKa(2) and hydroxido (pKa(3) and pKa(4)) bridges. A frozen solution EPR study shows a decrease in the signal intensity until an EPR silent spectrum is observed, upon increasing the basicity of the solution. The catalytic performance of the oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone was studied using UV-Vis-NIR absorption spectroscopic methods in CH3CN-H2O and in CH3OH-H2O at pH = 7.5, 8.0 and 8.5. A marked increase in activity, consistent with the formation of the hydroxide bridged species, is observed at pH = 8.5 in both solvent mixtures, but the activity is significantly higher in CH3OH-H2O.
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Affiliation(s)
- Edgar Mijangos
- Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, México D. F, 04510, México
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40
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Yi XY, Y. Sung HH, Williams ID, Leung WH. Cerium(iv)-containing oxomolybdenum cluster with a unique Ce6Mo9O38 core structure. Chem Commun (Camb) 2008:3269-71. [DOI: 10.1039/b800176f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Piñero D, Baran P, Boca R, Herchel R, Klein M, Raptis RG, Renz F, Sanakis Y. A pyrazolate-supported Fe(3)(mu(3)-O) core: structural, spectroscopic, electrochemical, and magnetic study. Inorg Chem 2007; 46:10981-9. [PMID: 18044951 PMCID: PMC2597296 DOI: 10.1021/ic0701460] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A comparison is made between the structural, spectroscopic, electrochemical, and magnetic properties of pyrazolate versus carboxylate complexes [Fe3(mu3(mu3O)(mu-LL)6Cl3]2- containing the Fe3(mu3-O)-motif. While the Fe3(mu3-O)-cores are structurally indistinguishable in the two types of complexes, their magnetic properties deviate from the expected values as a result of a through-pyrazole contribution to the overall antiferromagnetic exchange with J1/hc = -80.1 cm(-1) and J2/hc = -72.4 cm(-1), or J1/hc = 70.6 cm(-1) and J2/hc = -80.8 cm(-1), (Hex = -J1(S1S2 + S2S3) - J2S1S3). The magnetic properties of the pyrazolate complexes are further tuned by an antisymmetric exchange interaction term.
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Affiliation(s)
- Dalice Piñero
- Department of Chemistry and the Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00931-3346
| | - Peter Baran
- Department of Chemistry and the Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00931-3346
| | - Roman Boca
- Department of Inorganic Chemistry, Slovak University of Technology, SK-812 37 Bratislava, Slovakia
- Department of Inorganic Chemistry, Palacký University, Křížkovského 10, CZ-77147 Olomouc, Czech Republic
| | - Radovan Herchel
- Department of Chemistry, University of SS. Cyril and Methodius, Trnava, SK-91701, Slovakia
- Department of Inorganic Chemistry, Palacký University, Křížkovského 10, CZ-77147 Olomouc, Czech Republic
| | - Michael Klein
- Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg-University, D-55099 Mainz, Germany
| | - Raphael G. Raptis
- Department of Chemistry and the Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, PR 00931-3346
| | - Franz Renz
- Institute of Inorganic and Analytical Chemistry, Johannes Gutenberg-University, D-55099 Mainz, Germany
| | - Yiannis Sanakis
- Institute of Materials Science, NCRS “Demokritos”, 15310 Aghia Paraskevi, Athens, Greece
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42
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Kufelnicki A, Woźniczka M, Chęcińska L, Miernicka M, Budzisz E. Synthesis and structure of novel copper(II) complexes with pyrazole derived ligands and metal–ligand interaction in solution. Polyhedron 2007. [DOI: 10.1016/j.poly.2006.12.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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43
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Makarov SG, Piskunov AV, Suvorova ON, Schnurpfeil G, Domrachev GA, Wöhrle D. Near-Infrared Absorbing Ligand-Oxidized Dinuclear Phthalocyanines. Chemistry 2007; 13:3227-33. [PMID: 17201005 DOI: 10.1002/chem.200601164] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Ligand-oxidized annulated dinuclear phthalocyanine zinc(II) and lithium(I) complexes absorbing in the NIR region (lambda=1000-2200 nm) with high extinction coefficients are described. Analogous mononuclear Pc complexes were used for comparison. The oxidized Pcs were characterized in solution by electronic absorption, EPR and NMR spectra. The NIR transitions were explained by using MO diagrams calculated semiempirically. The reversible oxidation behavior of the phthalocyanine complexes was also estimated by cyclic voltammetry. These new extremely long wavelength absorbing phthalocyanines are interesting as materials with new electronic properties.
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Affiliation(s)
- Sergey G Makarov
- Institut für Organische und Makromolekulare Chemie Universität Bremen, P.O. Box 330440, 28334 Bremen, Germany
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44
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Belle C, Selmeczi K, Torelli S, Pierre JL. Chemical tools for mechanistic studies related to catechol oxidase activity. CR CHIM 2007. [DOI: 10.1016/j.crci.2006.10.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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45
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Koval IA, Selmeczi K, Belle C, Philouze C, Saint-Aman E, Gautier-Luneau I, Schuitema AM, van Vliet M, Gamez P, Roubeau O, Lüken M, Krebs B, Lutz M, Spek AL, Pierre JL, Reedijk J. Catecholase Activity of a Copper(II) Complex with a Macrocyclic Ligand: Unraveling Catalytic Mechanisms. Chemistry 2006; 12:6138-50. [PMID: 16832797 DOI: 10.1002/chem.200501600] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report the structure, properties and a mechanism for the catecholase activity of a tetranuclear carbonato-bridged copper(II) cluster with the macrocyclic ligand [22]pr4pz (9,22-dipropyl-1,4,9,14,17,22,27,28,29, 30-decaazapentacyclo[22.2.1.1(4,7).1(11,14). 1(17,20)]triacontane-5,7(28),11(29),12,18, 20(30),24(27),25-octaene). In this complex, two copper ions within a macrocyclic unit are bridged by a carbonate anion, which further connects two macrocyclic units together. Magnetic susceptibility studies have shown the existence of a ferromagnetic interaction between the two copper ions within one macrocyclic ring, and a weak antiferromagnetic interaction between the two neighboring copper ions of two different macrocyclic units. The tetranuclear complex was found to be the major compound present in solution at high concentration levels, but its dissociation into two dinuclear units occurs upon dilution. The dinuclear complex catalyzes the oxidation of 3,5-di-tert-butylcatechol to the respective quinone in methanol by two different pathways, one proceeding via the formation of semiquinone species with the subsequent production of dihydrogen peroxide as a byproduct, and another proceeding via the two-electron reduction of the dicopper(II) center by the substrate, with two molecules of quinone and one molecule of water generated per one catalytic cycle. The occurrence of the first pathway was, however, found to cease shortly after the beginning of the catalytic reaction. The influence of hydrogen peroxide and di-tert-butyl-o-benzoquinone on the catalytic mechanism has been investigated. The crystal structures of the free ligand and the reduced dicopper(I) complex, as well as the electrochemical properties of both the Cu(II) and the Cu(I) complexes are also reported.
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Affiliation(s)
- Iryna A Koval
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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46
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Pal Chaudhuri U, Whiteaker LR, Yang L, Houser RP. Multinuclear copper complexes of pyridylmethylamide ligands. Dalton Trans 2006:1902-8. [PMID: 16585978 DOI: 10.1039/b513763b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copper complexes of a family of pyridylmethylamide ligands HL(Ph), HL(Me3) and HL(Ph3) were synthesized and characterized [HL(Ph) = 2-phenyl-N-(2-pyridylmethyl)acetamide; HL(Me3) = 2,2-dimethyl-N-(2-pyridylmethyl)propionamide; HL(Ph3) = 2,2,2-triphenyl-N-(2-pyridylmethyl)acetamide]. The reaction of copper(II) salts with the HL family and triethylamine in methanol yields copper(II) complexes [Cu4(L(Ph))4(OH)2](ClO4)2 (1), [Cu2(HL(Me3))2(OMe)2(MeOH)2](OTf)2 (2) and [Cu2(HL(Ph3))2(OMe)2(MeOH)2](OTf)2 (3). The complexes have different nuclearity owing to varying steric properties of the ligands used. Complex 1 self-assembles in the presence of excess base to form a tetranuclear complex. Complexes 2 and 3 are binuclear and are bridged by a pair of methoxide ligands. Steric encumbrance of the ligands in 2 and 3 prevent cluster formation.
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Affiliation(s)
- Urmila Pal Chaudhuri
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, Oklahoma 73019, USA
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48
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Koval IA, Belle C, Selmeczi K, Philouze C, Saint-Aman E, Schuitema AM, Gamez P, Pierre JL, Reedijk J. Catecholase activity of a μ-hydroxodicopper(II) macrocyclic complex: structures, intermediates and reaction mechanism. J Biol Inorg Chem 2005; 10:739-50. [PMID: 16208496 DOI: 10.1007/s00775-005-0016-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Accepted: 07/29/2005] [Indexed: 10/25/2022]
Abstract
The monohydroxo-bridged dicopper(II) complex (1), its reduced dicopper(I) analogue (2) and the trans-mu-1,2-peroxo-dicopper(II) adduct (3) with the macrocyclic N-donor ligand [22]py4pz (9,22-bis(pyridin-2'-ylmethyl)-1,4,9,14,17,22,27,28,29,30- decaazapentacyclo -[22.2.1(14,7).1(11,14).1(17,20)]triacontane-5,7(28),11(29),12,18,20(30), 24(27),25-octaene), have been prepared and characterized, including a 3D structure of 1 and 2. These compounds represent models of the three states of the catechol oxidase active site: met, deoxy (reduced) and oxy. The dicopper(II) complex 1 catalyzes the oxidation of catechol model substrates in aerobic conditions, while in the absence of dioxygen a stoichiometric oxidation takes place, leading to the formation of quinone and the respective dicopper(I) complex. The catalytic reaction follows a Michaelis-Menten behavior. The dicopper(I) complex binds molecular dioxygen at low temperature, forming a trans-mu-1,2-peroxo-dicopper adduct, which was characterized by UV-Vis and resonance Raman spectroscopy and electrochemically. This peroxo complex stoichiometrically oxidizes a second molecule of catechol in the absence of dioxygen. A catalytic mechanism of catechol oxidation by 1 has been proposed, and its relevance to the mechanisms earlier proposed for the natural enzyme and other copper complexes is discussed.
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Affiliation(s)
- Iryna A Koval
- Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300, RA, Leiden, Netherlands
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49
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Tanase S, Koval IA, Bouwman E, de Gelder R, Reedijk J. Ligand Conformation Enforces Trigonal Bipyramidal Coordination Geometry in a New Dinuclear Bis(pyrazolato)-Bridged Copper(II) Complex: Synthesis, Crystal Structure, and Properties of [Cu(Npy2pz)]2(ClO4)2·2CH3CN. Inorg Chem 2005; 44:7860-5. [PMID: 16241135 DOI: 10.1021/ic050793w] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of Cu(ClO(4))(2).6H(2)O with the new tripodal ligand HNpy(2)pz (N-bis[(pyridin-2-yl)methyl][1H-pyrazol-3-yl)methyl]amine) in the presence of 1 equiv of triethylamine results in the formation of a doubly pyrazolato-bridged dicopper(II) complex, [Cu(Npy(2)pz)](2)(ClO(4))(2).2CH(3)CN (1). The crystal structure of 1 was determined by X-ray crystallography and was found to consist of two nearly identical discrete dinuclear molecules with bis(pyrazolato) bridges. The copper(II) ion has a trigonal bipyramid geometry achieved by the coordination of an aliphatic nitrogen, two pyridine moieties, and two pyrazolato nitrogens. Variable temperature-dependent magnetic data show that antiferromagnetic interactions operate in 1 as a result of the binding angle of the pyrazolato bridge. In solution, the stability of the dinuclear cation, [Cu(py(2)pz)](2)(2+), is highly dependent on the concentration, as indicated by ESI-MS, ligand field, cyclic voltammetry, EPR, and (1)H NMR studies.
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Affiliation(s)
- Stefania Tanase
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, The Netherlands
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