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Sarkar T, Kumar A, Sahoo S, Hussain A. Mixed-Ligand Cobalt(III) Complexes of a Naturally Occurring Coumarin and Phenanthroline Bases as Mitochondria-Targeted Dual-Purpose Photochemotherapeutics. Inorg Chem 2021; 60:6649-6662. [PMID: 33855849 DOI: 10.1021/acs.inorgchem.1c00444] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The bioessential nature of cobalt and the rich photochemistry of its coordination complexes can be exploited to develop potential next-generation photochemotherapeutics. A series of six novel mixed-ligand cobalt(III) complexes of the formulation [Co(B)2(L)]ClO4 (1-6), where B is an N,N-donor phenanthroline base, namely, 1,10-phenanthroline (phen in 1 and 4), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq in 2 and 5), and dipyrido[3,2-a:2',3'-c]phenazine (dppz in 3 and 6), and L is an O,O-donor dianionic ligand derived from catechol (1,2-dihydroxybenzene, cat2-, in 1-3) or esculetin (6,7-dihydoxycoumarin, esc2-, in 4-6), have been prepared and characterized, and their light-triggered cytotoxicity has been studied in cancer cells. The single-crystal X-ray diffraction structures of complexes 1 (as PF6- salt, 1a) and 2 show distorted octahedral geometries around the cobalt(III) center formed by the set of N4O2 donor atoms. The low-spin and 1:1 electrolytic complexes 1-6 display a d-d transition around 700 nm. Complexes 4-6 with a coordinated esc2- ligand additionally display a π → π* intraligand transition centered at 403 nm. Complexes 4-6 possessing a naturally occurring and photoactive esc2- ligand show high visible-light-triggered cytotoxicity against HeLa and MCF-7 cancer cells, yielding remarkably low micromolar IC50 values while being much less toxic under dark conditions. Control complexes 1-3 possessing the photoinactive cat2- ligand show significantly less cytotoxicity either in the presence of light or in the dark. The complex-induced cell death is apoptotic in nature caused by the formation of reactive oxygen species via a type 1 photoredox pathway. Fluorescence microscopy of HeLa cells treated with complex 6 reveals mitochondrial localization of the complex. A significant decrease in the dark toxicity of free esculetin and dppz base is observed upon coordination to cobalt(III). Complexes bind to calf-thymus DNA with significant affinity, but 6 binds with the greatest affinity. Complex 6 efficiently photocleaves supercoiled DNA to its nicked circular form when irradiated with visible light via a photoredox type 1 pathway involving hydroxyl radicals (HO•). Thus, complex 6 showing remarkable visible-light-triggered cytotoxicity but negligible toxicity in the dark is a good candidate for cancer photochemotherapy applications.
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Affiliation(s)
- Tukki Sarkar
- Department of Chemistry, Handique Girls' College, Guwahati 781001, Assam, India
| | - Arun Kumar
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Somarupa Sahoo
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Akhtar Hussain
- Department of Chemistry, Handique Girls' College, Guwahati 781001, Assam, India
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Thermal decomposition of bimetallic titanium complexes: A new method for synthesizing doped titanium nano-sized catalysts and photocatalytic application. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 97:813-826. [DOI: 10.1016/j.msec.2018.12.077] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/17/2018] [Accepted: 12/24/2018] [Indexed: 12/11/2022]
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Moreno M, Zacarias A, Porzel A, Velasquez L, Gonzalez G, Alegría-Arcos M, Gonzalez-Nilo F, Gross EKU. IR and NMR spectroscopic correlation of enterobactin by DFT. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 198:264-277. [PMID: 29550657 DOI: 10.1016/j.saa.2018.02.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 01/19/2018] [Accepted: 02/22/2018] [Indexed: 06/08/2023]
Abstract
Emerging and re-emerging epidemic diseases pose an ongoing threat to global health. Currently, Enterobactin and Enterobactin derivatives have gained interest, owing to their potential application in the pharmaceutical field. As it is known [J. Am. Chem. Soc (1979) 101, 20, 6097-6104], Enterobactin (H6EB) is an efficient iron carrier synthesized and secreted by many microbial species. In order to facilitate the elucidation of enterobactin and its analogues, here we propose the creation of a H6EB standard set using Density Functional Theory Infrared (IR) and NMR spectra. We used two exchange-correlation (xc) functionals (PBE including long-range corrections LC-PBE and mPW1), 2 basis sets (QZVP and 6-31G(d)) and 2 grids (fine and ultrafine) for most of the H6EB structures dependent of dihedral angles. The results show a significant difference between the OH and NH bands, while the CO amide and O(CO) IR bands are often found on top of each other. The NMR DFT calculations show a strong dependence on the xc functional, basis set, and grid used for the H6EB structure. Calculated 1H and 13C NMR spectra enable the effect of the solvent to be understood in the context of the experimental measurements. The good agreement between the experimental and the calculated spectra using LC-PBE/QZVP and ultrafine grid suggest the possibility of the systems reported here to be considered as a standard set. The dependence of electrostatic potential and frontier orbitals with the catecholamide dihedral angles of H6EB is described. The matrix-assisted laser desorption/ionization time of the flight mass spectrometry (MALDI-TOF MS) of H6EB is also reported of manner to enrich the knowledge about its reactivity.
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Affiliation(s)
- M Moreno
- University of the Basque Country, Barrio Sarriena, s/n, 48940 Leioa, Bizkaia, Spain.
| | - A Zacarias
- Max Planck Institute of Microstructure Physics, Weinberg 2, D 06120, Halle, Germany and ETSF
| | - A Porzel
- Leibniz Institute of Plant Biochemistry, Weinberg 3, D 06120 Halle, Germany
| | - L Velasquez
- Universidad Andres Bello, Facultad de Medicina, Center for Integrative Medicine and Innovative Science, Echaurren 183, Santiago, Chile
| | - G Gonzalez
- Center for Development of Nanoscience and Nanotechnology, CEDENNA, Casilla 653, Santiago, Chile; Universidad de Chile, Facultad de Ciencias, Departamento de Química, Laboratorio de Sintesis Inorganica y electroquímica, Las Palmeras 3425, Nuñoa, Santiago, Chile
| | - M Alegría-Arcos
- Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatic and Integrative Biology, Av Republica 239, Santiago, Chile; Centro Interdisciplinario de Neurociencias de Valparaíso (CINV), Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - F Gonzalez-Nilo
- Universidad Andres Bello, Facultad de Ciencias Biologicas, Center for Bioinformatic and Integrative Biology, Av Republica 239, Santiago, Chile
| | - E K U Gross
- Max Planck Institute of Microstructure Physics, Weinberg 2, D 06120, Halle, Germany and ETSF
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Gao Y, Pramanik A, Begum S, Sweet C, Jones S, Alamgir A, Ray PC. Multifunctional Biochar for Highly Efficient Capture, Identification, and Removal of Toxic Metals and Superbugs from Water Samples. ACS OMEGA 2017; 2:7730-7738. [PMID: 30023562 PMCID: PMC6044975 DOI: 10.1021/acsomega.7b01386] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 11/01/2017] [Indexed: 05/16/2023]
Abstract
According to the World Health Organization, more than two billion people in our world use drinking water sources which are not free from pathogens and heavy metal contamination. Unsafe drinking water is responsible for the death of several millions in the 21st century. To find facile and cost-effective routes for developing multifunctional materials, which has the capability to resolve many of the challenges associated with drinking water problem, here, we report the novel design of multifunctional fluorescence-magnetic biochar with the capability for highly efficient separation, identification, and removal of pathogenic superbugs and toxic metals from environmental water samples. Details of synthesis and characterization of multifunctional biochar that exhibits very good magnetic properties and emits bright blue light owing to the quantum confinement effect are reported. In our design, biochar, a carbon-rich low-cost byproduct of naturally abundant biomass, which exhibits heterogeneous surface chemistry and strong binding affinity via oxygen-containing group on the surface, has been used to capture pathogens and toxic metals. Biochar dots (BCDs) of an average of 4 nm size with very bright photoluminescence have been developed for the identification of pathogens and toxic metals. In the current design, magnetic nanoparticles have been incorporated with BCDs which allow pathogens and toxic metals to be completely removed from water after separation by an external magnetic field. Reported results show that owing to the formation of strong complex between multifunctional biochar and cobalt(II), multifunctional biochar can be used for the selective capture and removal of Co(II) from environmental samples. Experimental data demonstrate that multifunctional biochar can be used for the highly efficient removal of methicillin-resistant Staphylococcus aureus (MRSA) from environmental samples. Reported results also show that melittin, an antimicrobial peptide-attached multifunctional biochar, has the capability to completely disinfect MRSA superbugs after magnetic separation. A possible mechanism for the selective separation of Co(II), as well as separation and killing of MRSA, has been discussed.
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Davidson RA, Hao J, Rheingold AL, Miller JS. Reprint of: High spin ground state copper(II) and nickel(II) complexes possessing the 3,5-di-tert-butyl-1,2-semiquinonate radical anion. Polyhedron 2017. [DOI: 10.1016/j.poly.2017.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Davidson RA, Hao J, Rheingold AL, Miller JS. High spin ground state copper(II) and nickel(II) complexes possessing the 3,5-di-tert-butyl-1,2-semiquinonate radical anion. Polyhedron 2017. [DOI: 10.1016/j.poly.2017.05.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Rupp F, Chevalier K, Graf M, Schmitz M, Kelm H, Grün A, Zimmer M, Gerhards M, van Wüllen C, Krüger HJ, Diller R. Spectroscopic, Structural, and Kinetic Investigation of the Ultrafast Spin Crossover in an Unusual Cobalt(II) Semiquinonate Radical Complex. Chemistry 2017; 23:2119-2132. [DOI: 10.1002/chem.201604546] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Fabian Rupp
- Department of Physics; University of Kaiserslautern; Erwin Schrödinger Str. 46 67663 Kaiserslautern Germany
| | - Katharina Chevalier
- Department of Physics; University of Kaiserslautern; Erwin Schrödinger Str. 46 67663 Kaiserslautern Germany
| | - Michèle Graf
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Markus Schmitz
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Harald Kelm
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Anneken Grün
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Manuel Zimmer
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Markus Gerhards
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Christoph van Wüllen
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Hans-Jörg Krüger
- Department of Chemistry; University of Kaiserslautern; Erwin Schrödinger Str. 52 67663 Kaiserslautern Germany
| | - Rolf Diller
- Department of Physics; University of Kaiserslautern; Erwin Schrödinger Str. 46 67663 Kaiserslautern Germany
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Kim D, Kim BJ, Noh TH, Jung OS. New topological 3D copper(ii) coordination networks: catechol oxidation catalysis and solvent adsorption via porous properties. CrystEngComm 2015. [DOI: 10.1039/c5ce00087d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Attia AS, Abdel Aziz AA, Alfallous KA, El-Shahat M. New diethoxo-bridged dinuclear Cr(III) complexes with derivatives of the quinoxaline-2,3-dione ligand and 2,2′-bipyridine as a co-ligand: Syntheses, spectral characterizations, magnetic properties, antimicrobial inhibitory activities and interpretation of the electronic absorption spectra using the ZINDO/S-CI semi-empirical method. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.12.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Patricia TT, Sandra MV, Manuela L, Andrea L, Paolo F, Andrea D, Roberto R. Transient infrared spectroscopy: a new approach to investigate valence tautomerism. Phys Chem Chem Phys 2012; 14:1038-47. [DOI: 10.1039/c1cp22557j] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Suenaga Y, Hirano Y, Umehata Y, Minematsu T. Syntheses and characterization of Co(III) binuclear complexes with bis(catecholate) ligands containing an acetylene linker. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2010.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Milsmann C, Patra GK, Bill E, Weyhermüller T, DeBeer George S, Wieghardt K. Octahedral monodithiolene complexes of iron: characterization of S,S'-coordinated dithiolate(1-) pi radical monoanions: a spectroscopic and density functional theoretical investigation. Inorg Chem 2009; 48:7430-45. [PMID: 19572498 DOI: 10.1021/ic900936p] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of cis-[Fe(III)(cyclam)Cl(2)]Cl with 1 equiv of sodium N-diethyldithiocarbamate, toluene-3,4-dithiolate, and maleonitriledithiolate in methanol in the presence of triethylamine afforded the cations [Fe(III)(cyclam)(Et(2)dtc)](2+) (1), [Fe(III)(cyclam)(tdt)](+) (2), and [Fe(III)(cyclam)(mnt)](+) (3), which were isolated as triflate, hexafluorophosphate, and tetrafluoroborate salt, respectively, using sodium triflate, potassium hexafluorophosphate, or sodium tetrafluoroborate as the source for the counteranion. Complexes 1, 2, and 3 possess an S = (1)/(2) ground state (low-spin ferric d(5)). These salts were characterized by X-ray crystallography, UV-vis, Mössbauer, and electron paramagnetic resonance spectroscopies. Cyclic voltammetry revealed that 2 and 3 are reversibly one-electron-reduced, generating neutral 2(red) and 3(red), respectively, and one-electron-oxidized, generating dicationic 2(ox) and 3(ox), respectively. Fe and S K-edge X-ray absorption spectroscopy (XAS) revealed that 2 (S = (1)/(2)) and 2(ox) (S = 0) possess a low-spin ferric ion. Complexes 2 and 3 are S,S'-coordinated to a closed-shell dithiolate(2-) ligand, whereas 2(ox) and 3(ox) consist of a low-spin ferric ion antiferromagnetically coupled to a dithiolate(1-) pi radical ligand. They are singlet diradicals [Fe(III)(cyclam)(dithiolate(*))](2+). The analysis of the sulfur K pre-edge transitions reveals significant multiplet effects in the spectra of 2 and 2(ox), which provide rare experimental evidence for a singlet diradical description for 2(ox). Mössbauer spectroscopy on frozen solutions of 2(red) clearly show the presence of a high-spin ferrous ion (S = 2). The experimentally established electronic structures of the three members of the electron transfer series [Fe(cyclam)(dithiolate)](2+,+,0) have been verified by broken symmetry density functional theoretical calculations, which have been calibrated against the experiment by calculating XAS and Mössbauer spectra.
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Affiliation(s)
- Carsten Milsmann
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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Milsmann C, Bill E, Weyhermüller T, DeBeer George S, Wieghardt K. Electronic Structures of [RuII(cyclam)(Et2dtc)]+, [Ru(cyclam)(tdt)]+, and [Ru(cyclam)(tdt)]2+: An X-ray Absorption Spectroscopic and Computational Study (tdt = toluene-3,4-dithiolate; Et2dtc = N,N-diethyldithiocarbamate(1-)). Inorg Chem 2009; 48:9754-66. [PMID: 19769378 DOI: 10.1021/ic9011845] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Carsten Milsmann
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Eckhard Bill
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Thomas Weyhermüller
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer George
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Karl Wieghardt
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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Attia AS. Synthesis and spectroscopic studies on chromium(III) complex containing mixed-valence chrysenesemiquinone-chrysenecatecholate ligands and 2,2'-bipyridine coligand. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2007; 67:1339-45. [PMID: 17126590 DOI: 10.1016/j.saa.2006.10.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Accepted: 10/12/2006] [Indexed: 05/12/2023]
Abstract
The synthesis and spectroscopic properties of Cr(bpy)(chrySQ)(chryCat), a complex containing chromium(III) metal ion and chrysenequinone ligand in its partially reduced (chrySQ) and fully reduced (chryCat) forms, are described. The complex has been prepared by two different routes from Cr(CO)6 and Cr(chrySQ)3. Variable temperature magnetic susceptibility measurements indicated a strong antiferromagnetic coupling between Cr(III) (S=3/2) and chrysenesemiquinone radical (S=1/2), giving a magnetic coupling constant J=-342 cm(-1). Ligand-based redox couples were observed in the electrochemical studies that consist of quasi-reversible chrySQ/chryCat and bpy/bpy*- reductions and chryCat/chrySQ oxidation at negative potentials and irreversible chrySQ/chryBQ oxidation at positive potential. However, the metal was inert in the studied potential range. The electronic spectra of the complex revealed interesting properties. In addition to interaligand pi-pi* and n-pi* transitions, other bands corresponding to Cr(t(2g))-->chrySQ(pi*) and Cr(t(2g))-->bpy(pi*) metal-to-ligand charge-transfer MLCT transitions were observed. The infrared spectral analysis was informative in assigning the vibrations due to SQ and Cat ligands. Also, it was a useful tool in confirming the coordination of bpy ligand to chromium metal ion.
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Affiliation(s)
- Attia S Attia
- Chemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt.
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Attia AS. cis- and trans-Bis(pyridine)chromium(III) complexes containing mixed-valence chrysenesemiquinonate–chrysenecatecholate ligands: Synthesis, characterization and interpretation of the electronic absorption spectra using ZINDO/S method. Polyhedron 2007. [DOI: 10.1016/j.poly.2006.12.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kasumov VT, Taş E, Kartal I, Ucun F, Köksal F, Çukurovali A. COMPLEXATION OF METAL IONS WITH 3,5-DI-TERT-BUTYL-1,2-BENZOQUINONE-1-MONOOXIME, ESR STUDIES OF RADICAL INTERMEDIATES. J COORD CHEM 2006. [DOI: 10.1080/00958970108022588] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Veli T. Kasumov
- a Department of Chemistry , Harran University , Ş;anliurfa, Turkey
| | - Eşref Taş
- a Department of Chemistry , Harran University , Ş;anliurfa, Turkey
| | - Ibrahim Kartal
- b Physics Department , Ondokuz Mayis University , Samsun, Turkey
| | - Fatih Ucun
- b Physics Department , Ondokuz Mayis University , Samsun, Turkey
| | - Fevzi Köksal
- b Physics Department , Ondokuz Mayis University , Samsun, Turkey
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Anbalagan V, Srivastava T. Spectral and photophysical properties of mono and dinuclear Pt(II) and Pd(II) complexes: An unusual emission behaviour. Polyhedron 2004. [DOI: 10.1016/j.poly.2004.09.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Sever MJ, Wilker JJ. Visible absorption spectra of metal–catecholate and metal–tironate complexes. Dalton Trans 2004:1061-72. [PMID: 15252685 DOI: 10.1039/b315811j] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interactions between metals and catechol (1,2-dihydroxybenzene) or other ortho-dihydroxy moieties are being found in an increasing number of biological systems with functions ranging from metal ion internalization to biomaterial synthesis. Although metal-catecholate interactions have been studied in the past, we present the first systematic study of an array of these compounds, all prepared under identical conditions. We report the ultraviolet-visible absorption (UV-vis) spectra for catecholate and tironate complexes of the first row transition elements. Generation and identification of these species were accomplished by preparing aqueous solutions with varied ligand:metal ratios and subsequently titrating with base (NaOH). Controlled ligand deprotonation and metal binding resulted in sequential formation of complexes with one, two, and sometimes three catecholate or tironate ligands bound to a metal ion. We prepared the mono-, bis- and tris-catecholates and -tironates of Fe(3+), V(3+), V(4+)and Mn(3+), the mono- and bis-catecholates and -tironates of Cu(2+), Co(2+), Ni(2+), Zn(2+), Cr(2+) and Mn(2+), and several Ti(4+) and Cr(3+) species. The UV-vis spectra of each complex are described, some of which have not been reported previously. These data can now be applied to characterization of biological metal-catecholate systems.
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Affiliation(s)
- Mary J Sever
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907-2084, USA
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Ma T, Kojima T, Matsuda Y. Synthesis and characterization of a novel macrocyclic ligand containing catechol donor groups and its oxovanadium(IV) complex. Polyhedron 2000. [DOI: 10.1016/s0277-5387(00)00387-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Wheeler DE, McCusker JK. Electron Exchange and the Photophysics of Metal-Quinone Complexes. 1. Synthesis and Spectroscopy of Chromium-Quinone Dyads. Inorg Chem 1998; 37:2296-2307. [PMID: 11670388 DOI: 10.1021/ic971306i] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis, structural and spectroscopic characterization of monosemiquinone and monocatechol complexes of chromium(III) are described. Compounds of the general form [Cr(N(4))Q](n+), where N(4) represents a tetradentate or bis-bidentate nitrogenous ligand or ligands and Q represents a reduced form of an orthoquinone, have been prepared by two different routes from Cr(III) and Cr(II) starting materials. The complex [Cr(tren)(3,6-DTBSQ)](PF(6))(2), where tren is tris(2-aminoethyl)amine and 3,6-DTBSQ is 3,6-di-tert-butylorthosemiquinone, crystallizes in the monoclinic space group P2(1)/c with a = 11.9560(2) Å, b = 17.0715(4) Å, c = 17.1805(4) Å, beta = 90.167(1) degrees, V = 3506.6(1) Å(3), Z = 4, with R = 0.056 and R(w) = 0.070. Alternating C-C bond distances within the quinoidal ligand confirm its semiquinone character. Variable temperature magnetic susceptibility data collected on solid samples of both [Cr(tren)(3,6-DTBSQ)](PF(6))(2) and [Cr(tren)(3,6-DTBCat)](PF(6)) in the range 5-350 K exhibit temperature-independent values of 2.85 +/- 0.1 &mgr;(B) and 3.85 +/- 0.1 &mgr;(B), respectively. These data are consistent with a simple Cr(III)-catechol formulation (S = (3)/(2)) in the case of [Cr(tren)(3,6-DTBCat)](PF(6)) and strong antiferromagnetic coupling (|J| > 350 cm(-)(1)) between the Cr(III) and the semiquinone radical in [Cr(tren)(3,6-DTBSQ)](PF(6))(2). The absorption spectrum of the semiquinone complex exhibits a number of sharp, relatively intense transitions in fluid solution. Group theoretical arguments coupled with a qualitative ligand-field analysis including the effects of Heisenberg spin exchange suggest that several of the observed transitions are a consequence of exchange interactions in both the ground- and excited-state manifolds of the compound. The effect of electron exchange on excited-state dynamics has also been probed through static emission as well as time-resolved emission and absorption spectroscopies. It is suggested that the introduction of exchange coupling and subsequent change in the molecule's electronic structure may contribute to an increase of nearly 4 orders of magnitude in the rate of radiative decay (k(r)), and a factor of ca. 10(7) in the rate of nonradiative decay (k(nr)).
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Affiliation(s)
- Daniel E. Wheeler
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-1460
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Ruf M, Noll BC, Groner MD, Yee GT, Pierpont CG. Pocket Semiquinonate Complexes of Cobalt(II), Copper(II), and Zinc(II) Prepared with the Hydrotris(cumenylmethylpyrazolyl)borate Ligand. Inorg Chem 1997; 36:4860-4865. [PMID: 11670166 DOI: 10.1021/ic970244t] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
3,5-Di-tert-butyl-1,2-semiquinonate (3,5-DBSQ) complexes of Co(II), Cu(II), and Zn(II) have been prepared that contain the hydrotris(cumenylmethyl-pyrazolyl)borate (Tp(Cum,Me)) coligand. Tp(Cum,Me)Zn(3,5-DBSQ) and Tp(Cum,Me)Cu(3,5-DBSQ) were prepared by treating the parent hydroxide, Tp(Cum,Me)M(OH), M = Cu and Zn, with 3,5-di-tert-butylcatechol. Tp(Cum,Me)Co(3,5-DBSQ) was prepared by a reaction between (Tp(Cum,Me))(2)Co and 3,5-DBCat. The identity of (Tp(Cum,Me))(2)Co in this reaction was confirmed by a structure determination [(Tp(Cum,Me))(2)Co: orthorhombic, Pbcn, a = 17.7189(4) Å, b = 17.4806(3) Å, c = 25.7123(6) Å, V = 7964.1(3) Å(3), Z = 4, R(F) = 0.054]. Intersecting cumenyl substituents of the pyrazolylborate ligand encapsulate the Co(II) ion. Structural characterization on all three members of the Tp(Cum,Me)M(3,5-DBSQ) series has been carried out. The complexes of Co(II) and Zn(II) are isomorphous and isostructural [Tp(Cum,Me)Co(3,5-DBSQ): triclinic, P&onemacr;, a = 14.4631(2) Å, b = 18.5438(3) Å, c = 21.6142(2) Å, alpha = 79.8430(10) degrees, beta = 90.0900(10) degrees, gamma = 84.9900(10) degrees, V = 5683.45(13) Å(3), Z = 4, R(F) = 0.072; Tp(Cum,Me)Zn(3,5-DBSQ), triclinic, P&onemacr;, a = 14.261(3) Å, b = 18.760(7) Å, c = 21.710(4) Å, alpha = 80.049(12) degrees, beta = 89.853(8) degrees, gamma = 85.542(12) degrees, V = 5703(3) Å(3), Z = 4, R(F) = 0.064]. Tp(Cum,Me)Cu(3,5-DBSQ) [monoclinic, P2(1)/c, a = 19.3081(3) Å, b = 13.0291(2) Å, c = 21.4783(4) Å, beta = 102.8420(10) degrees, V = 5268.1(2) Å(3), Z = 4, R(F) = 0.071] has a distorted square pyramidal structure, the complexes of Zn and Co have structures that are closer to a trigonal bipyramid. Parent catecholate complexes of all three metals are unusually stable in air but undergo slow oxidation in solution to give the semiquinonate products characterized structurally. Copper(II) and SQ spins of Tp(Cum,Me)Cu(3,5-DBSQ) are located in orthogonal orbitals, and the complex has a S = 1 spin state. The charge distribution in Tp(Cum,Me)Co(3,5-DBSQ) is Co(II)-SQ, rather than the more common Co(III)-Cat, due to surprisingly weak donation by the Tp(Cum,Me) nitrogens.
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Affiliation(s)
- Michael Ruf
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309
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Spectroscopic and electrochemical studies of NiII, CuII, PdII and VOII complexes with naphthoquinonic ligands. Polyhedron 1997. [DOI: 10.1016/s0277-5387(96)00349-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Grillo VA, Hanson GR, Wang D, Hambley TW, Gahan LR, Murray KS, Moubaraki B, Hawkins CJ. Synthesis, X-ray Structural Determination, and Magnetic Susceptibility, Mössbauer, and EPR Studies of (Ph4P)2[Fe2(Cat)4(H2O)2]·6H2O, a Catecholato-Bridged Dimer of Iron(III). Inorg Chem 1996. [DOI: 10.1021/ic950499b] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vincent A. Grillo
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
| | - Graeme R. Hanson
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
| | - Deming Wang
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
| | - Trevor W. Hambley
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
| | - Lawrence R. Gahan
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
| | - Keith S. Murray
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
| | - Boujemaa Moubaraki
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
| | - Clifford J. Hawkins
- Chemistry Department and Centre for Magnetic Resonance, The University of Queensland, Brisbane, QLD 4072 Australia, The School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia, and Chemistry Department, Monash University, Clayton, Victoria 3168, Australia
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Camus J, Meghea A, Anacona J. EPR spectra of copper complexes with quinoxalinic and naphthoquinonic ligands. Polyhedron 1996. [DOI: 10.1016/0277-5387(95)00573-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Attia AS, Junga OS, Pierpont CG. Valence tautomerism for catechol/semiquinone complexes of the trans-M(Bupy)2(3,6-DBQ)2 (MMn, Fe, Co) series. Inorganica Chim Acta 1994. [DOI: 10.1016/0020-1693(94)04074-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Anbalagan V, Srivastava T. Spectral and photochemical behaviour of newly synthesized 2,2′-dipyridylamine complexes of Pt(II) and Pd(II) with various dioxolenes. J Photochem Photobiol A Chem 1994. [DOI: 10.1016/1010-6030(94)80037-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Anbalagan V, Srivastava T. Synthesis, spectral and electrochemical behaviour of α-diimine complexes of platinum(II) and palladium(II) with 3,4-dihydroxybenzoic acid. Polyhedron 1994. [DOI: 10.1016/s0277-5387(00)86605-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ruthenium(II) Complexes of O,N-donor Schiff base ligands and their use as catalytic organic oxidants. Polyhedron 1993. [DOI: 10.1016/s0277-5387(00)83051-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Nakashima S, Ohya-Nishiguchi H, Hirota N, Tsuboyama S, Chijimatsu T. The Role of a Spin-Coupled Intermediate in a System Consisting of Tetraminecobalt(III) Complexes and Catechols –A Model Intermediate of Dioxygenase Reaction–. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1992. [DOI: 10.1246/bcsj.65.1225] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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La Monica G, Angaroni MA, Cariati F, Cenini S, Ardizzoia GA. Oxidation reaction of the copper(I) phenoxo complex [(phen)(Ph3P)Cu(OPH)]: The formation of the copper(II) derivative [(phen)Cu(OPh(OC6H4-2-(OH)], having a catecholate group derived from phenol hydroxylation reaction. Inorganica Chim Acta 1988. [DOI: 10.1016/s0020-1693(00)86020-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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