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D'Elios MM, Aldinucci A, Amoriello R, Benagiano M, Bonechi E, Maggi P, Flori A, Ravagli C, Saer D, Cappiello L, Conti L, Valtancoli B, Bencini A, Menichetti L, Baldi G, Ballerini C. Myelin-specific T cells carry and release magnetite PGLA–PEG COOH nanoparticles in the mouse central nervous system. RSC Adv 2018; 8:904-913. [PMID: 35538965 PMCID: PMC9076978 DOI: 10.1039/c7ra11290d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 12/13/2017] [Indexed: 11/21/2022] Open
Abstract
Progress in nanotechnology has determined new strategies concerning drug delivery into the central nervous system for the treatment of degenerative and inflammatory diseases. To date, brain targeting through systemic drug administration, even in a nano-composition, is often unsuccessful. Therefore, we investigated the possibility of loading T lymphocytes with PGLA–PEG COOH magnetite nanoparticles (30 nm), which can be built up to easily bind drugs and monoclonal antibodies, and to exploit the ability of activated T cells to cross the blood–brain barrier and infiltrate the brain parenchyma. Iron oxide nanoparticles have been widely used in biomedical applications due to their theranostic properties and are therefore a well-established nanomaterial. The magnetite core is easily hybridized with polymeric compounds that may enhance the possibility of the nanoparticles entering cells with low phagocytic properties. Taking advantage of these material characteristics, after in vitro assessment of the viability and functionality of nano-loaded MOG35–55 specific T cells, we transferred cells containing the nano-cargo into naïve mice affected by experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. By means of histological and immunohistological methods, we were able to identify the nano-loaded T cells in the central nervous system. Our data demonstrated that T cells containing nanomaterials hold the possibility of carrying and releasing nanoparticles in the brain. Magnetite nanoparticles enter non-phagocytic myelin-specific T cells and reach the central nervous system after in vivo transfer.![]()
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Affiliation(s)
- M. M. D'Elios
- Department of Clinical and Experimental Medicine
- University of Florence
- Italy
| | - A. Aldinucci
- Department of Neuroscience, Psychology, Drug and Child Health
- University of Florence
- Italy
| | - R. Amoriello
- Department of Neuroscience, Psychology, Drug and Child Health
- University of Florence
- Italy
| | - M. Benagiano
- Department of Clinical and Experimental Medicine
- University of Florence
- Italy
| | - E. Bonechi
- Department of Neuroscience, Psychology, Drug and Child Health
- University of Florence
- Italy
| | - P. Maggi
- Department of Neurology
- Hôpital CHU Brugmann-Université libre de Bruxelles-Bruxelles-Be
- Belgium
| | - A. Flori
- Fondazione CNR Regione Toscana G. Monasterio
- Pisa
- Italy
| | - C. Ravagli
- Research Center Colorobbia
- Cericol, Colorobbia Consulting
- Florence
- Italy
| | - D. Saer
- Research Center Colorobbia
- Cericol, Colorobbia Consulting
- Florence
- Italy
| | - L. Cappiello
- Research Center Colorobbia
- Cericol, Colorobbia Consulting
- Florence
- Italy
| | - L. Conti
- Department of Chemistry Ugo Schiff
- University of Florence
- Italy
| | - B. Valtancoli
- Department of Chemistry Ugo Schiff
- University of Florence
- Italy
| | - A. Bencini
- Department of Chemistry Ugo Schiff
- University of Florence
- Italy
| | | | - G. Baldi
- Research Center Colorobbia
- Cericol, Colorobbia Consulting
- Florence
- Italy
| | - C. Ballerini
- Department of Neuroscience, Psychology, Drug and Child Health
- University of Florence
- Italy
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Nistri S, Boccalini G, Bencini A, Becatti M, Valtancoli B, Conti L, Lucarini L, Bani D. A new low molecular weight, MnII-containing scavenger of superoxide anion protects cardiac muscle cells from hypoxia/reoxygenation injury. Free Radic Res 2014; 49:67-77. [PMID: 25348343 DOI: 10.3109/10715762.2014.979168] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Reperfusion injury after oxygen starvation is a key pathogenic step in ischemic diseases. It mainly consists in oxidative stress, related to mitochondrial derangement and enhanced generation of reactive oxygen species (ROS), mainly superoxide anion (O2(•2)), and peroxynitrite by cells exposed to hypoxia. This in vitro study evaluates whether Mn(II)(4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate).2H2O, or Mn(II)(Me2DO2A), a new low molecular weight, Mn(II)-containing O2(•) scavenger, has a direct protective action on H9c2 rat cardiac muscle cells subjected to hypoxia and reoxygenation. Mn(II)(Me2DO2A) (1 and 10 μmol/l) was added to the culture medium at reoxygenation and maintained for 2 h. In parallel experiments, the inactive congener Zn(II)(Me2DO2A), in which Zn(II) replaced the functional Mn(II) center in the same organic scaffold, was used as negative control. Mn(II)(Me2DO2A) (10 μmol/l) significantly increased cardiac muscle cell viability (trypan blue assay), improved mitochondrial activity (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide test, membrane potential Δψ), reduced apoptosis (mitochondrial permeability transition pore opening, caspase-3, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling assay), decreased intracellular ROS levels (2',7'-dichlorodihydrofluorescein diacetate and MitoSOX assays), and decreased protein nitroxidation (nitrotyrosine [NT] expression) and DNA oxidation (8-hydroxy-deoxyguanosine levels). Of note, Zn(II)(Me2DO2A) had no protective effect. The mechanism of Mn(II)(Me2DO2A) relies on concentration-dependent removal of harmful O2(•) generated at reoxygenation from dysfunctional mitochondria in hypoxia-induced cells, as indicated by the MitoSOX assay. This study suggests that Mn(II)(Me2DO2A) is a promising antioxidant drug capable of reducing O2(•)-mediated cell oxidative stress which occurs at reoxygenation after hypoxia. In perspective, Mn(II)(Me2DO2A) might be used to reduce ischemia-reperfusion organ damage in acute vascular diseases, as well as to extend the viability of explanted organs before transplantation.
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Affiliation(s)
- S Nistri
- Department of Experimental & Clinical Medicine, Section of Anatomy & Histology, Research Unit of Histology & Embryology, University of Florence , Florence , Italy
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Bani D, Bencini A. Developing ROS scavenging agents for pharmacological purposes: recent advances in design of manganese-based complexes with anti-inflammatory and anti- nociceptive activity. Curr Med Chem 2013; 19:4431-44. [PMID: 22830332 DOI: 10.2174/092986712803251476] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Revised: 06/05/2012] [Accepted: 06/05/2012] [Indexed: 11/22/2022]
Abstract
Reactive oxygen and nitrogen species, which are normal products of cell metabolism, may play a dual beneficial/deleterious role, depending on local concentration and mode of generation. As such, they have been identified as key pathogenic factors for many inflammatory and degenerative disorders, carcinogenesis, nociception and ageing. In this perspective, low molecular weight transition metal complexes with organic ligands have been and are still viewed as promising pharmaceutical agents with antioxidant/free radical scavenging properties, owing to their ability to interact and/or react with reactive oxygen or nitrogen species and counterbalance excessive endogenous free radical generation in biological systems. Among these compounds, manganese(II/III) complexes have resulted effective as ROS scavengers both in vitro and in vivo. In particular, Mn(III) complexes with porphyrins and salen derivatives as well as Mn(II) complexes with macrocyclic pentaamines and polyamine-polycarboxylic acids have been recently analyzed as ROS scavengers for therapeutic purposes. In this article, we summarize the chemical and biological properties of manganese complexes with low molecular weight synthetic ligands as scavengers of pro-oxidant species, with particular attention to the mechanisms operating at the metal center in the scavenging process. A proper design of the organic scaffolds may yield manganese complexes capable to catalyze different scavenging reactions, including superoxide and/or hydrogen peroxide dismutation and peroxynitrite decomposition. These manganese complexes can be viewed either as a novel class of drugs helpful to reduce oxidative tissue injury or as useful tools to get further light on the role played by ROS in biological systems.
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Affiliation(s)
- D Bani
- Department of Anatomy, Histology & Forensic Medicine, University of Florence, V.le G.Pieraccini, 6 - I-50139 Firenze, Italy
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Bencini A, Gatteschi D. X.alpha.-SW calculations of the electronic structure and magnetic properties of weakly coupled transition-metal clusters. The [Cu2Cl6]2- dimers. J Am Chem Soc 2012; 108:5763-71. [PMID: 22175325 DOI: 10.1021/ja00279a017] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Claiser N, Souhassou M, Lecomte C, Gillon B, Carbonera C, Caneschi A, Dei A, Gatteschi D, Bencini A, Pontillon Y, Lelièvre-Berna E. Combined charge and spin density experimental study of the yttrium(III) semiquinonato complex Y(HBPz3)2(DTBSQ) and DFT calculations. J Phys Chem B 2007; 109:2723-32. [PMID: 16851280 DOI: 10.1021/jp0467907] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High-resolution X-ray diffraction and polarized neutron diffraction experiments have been performed on the Y-semiquinonate complex, Y(HBPz3)2(DTBSQ), in order to determine the charge and spin densities in the paramagnetic ground state, S = (1/2). The aim of these combined studies is to bring new insights to the antiferromagnetic coupling mechanism between the semiquinonate radical and the rare earth ion in the isomorphous Gd(HBPz3)2(DTBSQ) complex. The experimental charge density at 106 K yields detailed information about the bonding between the Y3+ ion and the semiquinonate ligand; the topological charge of the yttrium atom indicates a transfer of about 1.5 electrons from the radical toward the Y3+ ion in the complex, in agreement with DFT calculations. The electron density deformation map reveals well-resolved oxygen lone pairs with one lobe polarized toward the yttrium atom. The determination of the induced spin density at 1.9 K under an applied magnetic field of 9.5 T permits the visualization of the delocalized magnetic orbital of the radical throughout the entire molecule. The spin is mainly distributed on the oxygen atoms [O1 (0.12(1) mu B), O2(0.11(1) mu B)] and the carbon atoms [C21 (0.24(1) mu B), C22(0.20(1) mu B), C24(0.16(1) mu B), C25(0.12(1) mu B)] of the carbonyl ring. A significant spin delocalization on the yttrium site of 0.08(2) mu B is observed, proving that a direct overlap with the radical magnetic orbital can occur at the rare earth site and lead to antiferromagnetic coupling. The DFT calculations are in good quantitative agreement with the experimental charge density results, but they underestimate the spin delocalization of the oxygen toward the yttrium and the carbon atoms of the carbonyl ring.
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Affiliation(s)
- N Claiser
- Laboratoire de Cristallographie et Modélisation des Matériaux Minéraux et Biologiques, UMR CNRS 7036, Université Henri Poincaré-Nancy I, BP 239, F-54506 Vandoeuvre-les-Nancy Cedex, France
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Adamo C, Barone V, Bencini A, Broer R, Filatov M, Harrison NM, Illas F, Malrieu JP, Moreira IDPR. Comment on “About the calculation of exchange coupling constants using density-functional theory: The role of the self-interaction error” [J. Chem. Phys. 123, 164110 (2005)]. J Chem Phys 2006; 124:107101; author reply 107102. [PMID: 16542105 DOI: 10.1063/1.2178791] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Bencini A, Gatteschi D, Zanchini C, Haase W. Anisotropic exchange in transition-metal dinuclear complexes. 7. Bis[.mu.-2-(diethylamino)ethanolato]dibromodicopper(II). Inorg Chem 2002. [DOI: 10.1021/ic00215a036] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Benelli C, Gatteschi D. Single-crystal polarized electronic spectra of the dimeric tetrakis(.mu.-benzoato-O,O')-bis(quinoline)dicobalt(II). Inorg Chem 2002. [DOI: 10.1021/ic50189a076] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Gatteschi D. Ligand field spin-orbit coupling calculations for d7, d8, d9 (d3, d2, d1) five coordinated complexes of C3v symmetry. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100560a015] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Gatteschi D, Zanchini C, Haasnoot JG, Prins R, Reedijk J. EPR spectra of binuclear triazolato- and imidazolato-bridged copper(II) complexes including the four-copper form of bovine erythrocyte superoxide dismutase. Inorg Chem 2002. [DOI: 10.1021/ic00212a022] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Banci L, Bencini A, Gatteschi D. Dynamic behavior of the adduct of copper(II) bis(hexafluoroacetylacetonate) with a bidentate complex ligand. Inorg Chem 2002. [DOI: 10.1021/ic00134a060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Gatteschi D, Zanchini C. Anisotropic exchange in transition-metal dinuclear complexes. 8. Bis(.mu.-pyridine N-oxide)bis[dichloro(dimethyl sulfoxide)copper(II)]. Inorg Chem 2002. [DOI: 10.1021/ic00233a023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Benelli C, Caneschi A, Carlin RL, Dei A, Gatteschi D. Crystal and molecular structure of and magnetic coupling in two complexes containing gadolinium(III) and copper(II) ions. J Am Chem Soc 2002. [DOI: 10.1021/ja00312a054] [Citation(s) in RCA: 466] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Banci L, Bencini A, Gatteschi D. Correlation between anisotropic exchange and structure of di-μ-hydroxy bridged copper(II) complexes. J Am Chem Soc 2002. [DOI: 10.1021/ja00342a017] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Banci L, Bencini A, Dei A, Gatteschi D. EPR spectra of and exchange interactions in trinuclear complexes. 2. Metal(II) adducts of tetradentate Schiff base copper(II) complexes. Inorg Chem 2002. [DOI: 10.1021/ic00168a040] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Gatteschi D. Single-crystal polarized electronic and electron spin resonance spectra of the trigonal-bipyramidal complex aquobis(1,10-phenanthroline)copper(II) nitrate. Inorg Chem 2002. [DOI: 10.1021/ic50174a033] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Benelli C, Gatteschi D, Zanchini C. .pi.-Bonding interactions of nonlinearly ligating ligands with octahedral cobalt(II) complexes. Inorg Chem 2002. [DOI: 10.1021/ic00157a007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bencini A, Benelli C, Dei A, Gatteschi D. EPR spectra of and exchange interactions in trinuclear complexes. 3. Synthesis, crystal structure and magnetic properties of the oxovanadium(IV) adduct of a tetradentate Schiff base copper(II) complex. Inorg Chem 2002. [DOI: 10.1021/ic00199a012] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bencini A, Benelli C, Gatteschi D, Zanchini C. ESR spectra of low-symmetry high-spin cobalt(II) complexes. 2. Pseudotetrahedral dichlorobis(triphenylphosphine oxide)cobalt(II). Inorg Chem 2002. [DOI: 10.1021/ic50198a017] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Banci L, Bencini A, Benelli C, Dei A, Gatteschi D. ESR spectra of nickel(II)-copper(II) and nickel(II)-cobalt(II) exchange-coupled pairs in transition-metal dinuclear triketonate complexes. Inorg Chem 2002. [DOI: 10.1021/ic50219a014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Benelli C, Gatteschi D, Zanchini C. ESR spectra of low-symmetry high-spin cobalt(II) complexes. 6. 6-Methylquinoline, pyridine, and water adducts of cobalt(II) acetylacetonate. Inorg Chem 2002. [DOI: 10.1021/ic50212a037] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Banci L, Bencini A, Benelli C, Di Vaira M, Gatteschi D. Crystal structure and magnetic properties of the tetranuclear [Cu(SALMedpt)Cu(hfa)2]2.0.6CHCl3 complex, formed by hexafluoroacetylacetonate and by the pentadentate N,N'-[4-methyl-4-azaheptane-1,7-diyl]bis(salicylaldiminate) ligand. Inorg Chem 2002. [DOI: 10.1021/ic00140a040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Benelli C, Gatteschi D, Zanchini C. ESR spectra of low-symmetry high-spin cobalt(II) complexes. 3. Square-pyramidal nitratotetrakis(methyldiphenylarsine oxide)cobalt(II) nitrate. Inorg Chem 2002. [DOI: 10.1021/ic50199a038] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Benelli C, Gatteschi D. Preparation of [Co2(tren)2OH](ClO4)3.H2O (tren = tris(2-aminoethyl)amine) and magnetic exchange interactions in binuclear monohydroxo-bridged copper(II) and cobalt(II) complexes. Inorg Chem 2002. [DOI: 10.1021/ic00145a020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bencini A, Gatteschi D, Reedijk J, Zanchini C. Anisotropic exchange in transition-metal dinuclear complexes. 4. (.mu.-Benzotriazolato-N1,N3)bis[[tris(N1-methylbenzimidazol-2-ylmethyl)amine-N,N3,N3',N3'']copper(II)]trinitrate. Inorg Chem 2002. [DOI: 10.1021/ic00196a018] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Benelli C, Caneschi A, Dei A, Gatteschi D. Crystal and molecular structure and magnetic properties of a trinuclear complex containing exchange-coupled GdCu2 species. Inorg Chem 2002. [DOI: 10.1021/ic00224a036] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Gatteschi D. Electron spin resonance spectra of low-symmetry pseudotetrahedral high-spin cobalt(II) complexes. Tetra-n-butylammonium tribromo(quinoline)cobaltate(II). Inorg Chem 2002. [DOI: 10.1021/ic50174a071] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Di Vaira M, Fabretti AC, Gatteschi D, Zanchini C. Anisotropic exchange in transition-metal dinuclear complexes. 2. Crystal and molecular structure and EPR spectra of a dinuclear copper oxamidato complex. Inorg Chem 2002. [DOI: 10.1021/ic00179a033] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Caneschi A, Dei A, Gatteschi D, Zanchini C, Kahn O. Low-lying electronic energy levels in a series of heterodinuclear complexes containing octahedral nickel(II) and tetrahderal metal(II) (copper, cobalt, and manganese) species. Inorg Chem 2002. [DOI: 10.1021/ic00229a016] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Gatteschi D, Zanchini C. Anisotropic exchange in transition-metal dinuclear complexes. 5. Bis(-.mu.-hydroxo)bis[(2-methylimidazole)copper(II)] diperchlorate dihydrate. Inorg Chem 2002. [DOI: 10.1021/ic00199a013] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Benelli C, Gatteschi D, Zanchini C. ESR spectra of low-symmetry high-spin cobalt(II) complexes. 7. Trigonal-bipyramidal pentakis(picoline N-oxide)cobalt(II) perchlorate. Inorg Chem 2002. [DOI: 10.1021/ic50214a050] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Benelli C, Fabretti AC, Franchini G, Gatteschi D. Magnetic properties and crystal structure of a linear-chain copper(II) compound with bridging acetate and oxamidate ligands. Inorg Chem 2002. [DOI: 10.1021/ic00227a036] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Benelli C, Gatteschi D, Zanchini C. Magnetic coupling in a linear-chain copper(II)-imidazolate compound. Mechanism of the exchange interaction through bridging imidazolate ligands. Inorg Chem 2002. [DOI: 10.1021/ic00223a038] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bencini A, Benelli C, Gatteschi D, Zanchini C. Electron spin resonance spectra of low-symmetry high-spin cobalt(II) complexes. 4. Tetragonal-octahedral dichlorotetrakis(pyridine)- and dichlorotetrakis(pyrazole)cobalt(II). Inorg Chem 2002. [DOI: 10.1021/ic50207a038] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bencini A, Gatteschi D, Zanchini C. Anisotropic exchange in transition-metal dinuclear complexes. 6. Bis(-.mu.-chloro)bis(dichlorocuprates(II)). Inorg Chem 2002. [DOI: 10.1021/ic00199a014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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39
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Bencini A, Gatteschi D, Sacconi L. Electron spin resonance investigation of the mixed-valence dinuclear tetra(.mu.-1,8-naphthyridine-N,N')-bis(bromonickel) tetraphenylborate complex. Inorg Chem 2002. [DOI: 10.1021/ic50187a058] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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Banci L, Bencini A, Gatteschi D. Anisotropic exchange in transition-metal dinuclear complexes. 3. Bis(.mu.-(1,3-azido)bis(1,1,4,7,7-pentamethyldiethylenetriamine)dicopper(II) bis(tetraphenylborate). Inorg Chem 2002. [DOI: 10.1021/ic00182a030] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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41
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Lodeiro C, Pina F, Parola AJ, Bencini A, Bianchi A, Bazzicalupi C, Ciattini S, Giorgi C, Masotti A, Valtancoli B, de Melo JS. Exploring the photocatalytic properties and the long-lifetime chemosensor ability of Cl(2)[Ru(Bpy)(2)L] (L = 2,5,8,11,14-pentaaza[15])-2,2'-bipyridilophane). Inorg Chem 2001; 40:6813-9. [PMID: 11735495 DOI: 10.1021/ic0105213] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work a new water-soluble long-lifetime chemosensor, containing a polyamine unit connected to a complexed Ru(II) metal center, is described. Its crystal structure has been characterized by X-ray analysis. The polyamine macrocyclic unit is capable of anchoring cationic or anionic substrates, according to its protonation state. Examples of electron transfer involving the ruthenium complex core and the bound substrate are presented. The photocatalytic ability of such a system is illustrated by the oxidation of iodide to iodine promoted by light absorption at 436 nm.
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Affiliation(s)
- C Lodeiro
- Departamento de Química, Centro de Química-Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre 2825 Monte de Caparica, Portugal
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42
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Arranz P, Bazzicalupi C, Bencini A, Bianchi A, Ciattini S, Fornasari P, Giorgi C, Valtancoli B. Cd(II) and Pb(II) complexation by dipyridine-containing macrocycles with different molecular architecture. Effect of complex protonation on metal coordination environment. Inorg Chem 2001; 40:6383-9. [PMID: 11720491 DOI: 10.1021/ic010597z] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The coordination features of the three dipyridine-containing polyamine macrocycles 2,5,8,11,14-pentaaza[15]-[15](2,2')[1,15]-bipyridylophane (L1), 5,8,11-trimethyl-2,5,8,11,14-pentaaza[15]-[15](2,2')[1,15]-bipyridylophane (L2), and 4,4'-(2,5,8,11,14-pentaaza[15]-[15](2,2')-bipyridylophane) (L3) toward Cd(II) and Pb(II) have been studied by means of potentiometric, microcalorimetric, and spectrophotometric UV-vis titrations in aqueous solutions. All ligands form 1:1 metal complexes. In the L1 and L2 complexes the metals are lodged inside the macrocyclic cavity, coordinated to the heteroaromatic nitrogens. On the other hand, the insertion of a rather rigid dipyridine moiety within a macrocyclic structure does not allow all the aliphatic amine groups to coordinate to the metals and several protonated complexes are found in solution. The particular molecular architecture of L3, which displays two well-separated binding moieties, strongly affects its coordination behavior. In the [PbL3](2+) complex and in its protonated species, the metal is lodged inside the macrocyclic cavity, not bound to the heteroaromatic nitrogens. A similar coordination environment is found in [CdL3](2+). In this case, however, protonation of the complex takes place on the aliphatic amine groups and gives rise to translocation of the metal outside the cavity, coordinated by the dipyridine moiety.
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Affiliation(s)
- P Arranz
- Department of Inorganic and Organic Chemistry, University of Jaen, Jaen, Spain
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43
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Bazzicalupi C, Bencini A, Berni E, Bianchi A, Giorgi C, Fusi V, Valtancoli B, Lodeiro C, Roque A, Pina F. Coordination properties of a polyamine cryptand with two different binding moieties. A case of a pH-modulated antenna device based on a new Eu(III) cryptate complex. Inorg Chem 2001; 40:6172-9. [PMID: 11703116 DOI: 10.1021/ic010638r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protonation and alkali- and alkaline-earth-metal coordination by the dipyridine-containing cryptand L have been studied by means of potentiometric and spectroscopic (UV-vis, (1)H NMR) measurements in aqueous solutions. This ligand is constituted by an aliphatic polyamine chain and a coordinating cleft, delimited by two dipyridine units, where the metal ion is lodged. The resulting complexes are characterized by an unusually high stability. The polyamine chain is not involved, or weakly involved, in metal coordination, and facile protonation can occur on the nitrogen atoms of this moiety. Similar coordination features are found in the Eu(III) complex. A fluorescence emission study reveals that the Eu(III) cryptate shows the characteristic visible emission of the metal, due to the intramolecular energy transfer to the metal ion mainly from the lower energy triplet state of the cryptand. On the other hand, the emission intensity is modulated by pH, giving a maximum at neutral pH and decreasing at both acidic and alkaline pH values.
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Affiliation(s)
- C Bazzicalupi
- Department of Chemistry, University of Florence, Via Maragliano 75/77, 50144 Florence, Italy
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Lodeiro C, Parola AJ, Pina F, Bazzicalupi C, Bencini A, Bianchi A, Giorgi C, Masotti A, Valtancoli B. Protonation and Zn(II) coordination by dipyridine-containing macrocycles with different molecular architecture. A case of pH-controlled metal jumping outside-inside the macrocyclic cavity. Inorg Chem 2001; 40:2968-75. [PMID: 11399162 DOI: 10.1021/ic001381k] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of the macrocyclic ligand 4,4'-(2,5,8,11,14-pentaaza[15])-2,2'-bipyridylophane (L3), which contains a pentaamine chain linking the 4,4'-positions of a 2,2'-dipyridine moiety, is reported. Protonation and Zn(II) complexation by L3 and by macrocycle L2, containing the same pentaamine chain connecting the 6,6'-positions of 2,2'-dipyridine, were studied by means of potentiometric, UV-vis, and fluorescent emission measurements. While in L2 all the nitrogen donor atoms are convergent inside the macrocyclic cavity, in L3 the heteroaromatic nitrogen atoms are located outside. Both ligands form mono- and dinuclear Zn(II) complexes in aqueous solution. In the mononuclear Zn(II) complexes with L2, the metal is coordinated inside the macrocyclic cavity, bound to the heteroaromatic nitrogen donors and three amine groups of the aliphatic chain. As shown by the crystal structure of the [ZnL2](2+) complex, the two benzylic nitrogens are not coordinated and facile protonation of the complex takes place at slightly acidic pH values. Considering the mononuclear [ZnL3](2+) complex, the metal is encapsulated inside the cavity, not coordinated by the dipyridine unit. Protonation of the complex occurs on the aliphatic polyamine chain and gives rise to translocation of the metal outside the cavity, bound to the heteroaromatic nitrogens.
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Affiliation(s)
- C Lodeiro
- Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre 2825 Monte de Caparica, Lisbon, Portugal
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45
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Bencini A, Daul CA, Dei A, Mariotti F, Lee H, Shultz DA, Sorace L. Charge distribution in bis-dioxolene radical metal complexes. synthesis and DFT characterization of dinuclear Co(III) and Cr(III) complexes with a mixed-valent, S = 1/2 semiquinone-catecholate ligand. Inorg Chem 2001; 40:1582-90. [PMID: 11261968 DOI: 10.1021/ic0007052] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bis-dioxolene bridged dinuclear metal complexes of general formula M2(CTH)2(diox-diox)(PF6)n (n = 2, 3; M = Co(III), Cr(III); CTH = tetraazamacrocycle) have been synthesized using the bis-bidentate ligand 5,5'-di-tert-butyl-3,3',4,4'-tetrahydroxybiphenyl. These complexes were characterized by means of ESR, UV-vis, temperature dependent magnetic susceptibility, and cyclic voltammetry. Our results unambiguously suggest that the tripositive dimetal cations can be described as containing a fully delocalized bis-dioxolene trinegative radical ligand (Cat-Sq) bridging two tripositive metal cations. In this frame the sextet electronic ground state characterizes the Cr2(CTH)2(Cat-SQ)3+ as a result of the antiferromagnetic coupling of the radical bridging ligand with the two equivalent paramagnetic metal centers. The electronic and geometrical structure and the magnetic properties of Cat-Sq and of its complexes have been studied with density functional theory.
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Affiliation(s)
- A Bencini
- Dipartimento di Chimica, Università di Firenze, Firenze, Italy
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Abstract
The stability constants of Cu(II) complexes that consist of either an oxaaza macrocycle with two triamine moieties linked by dioxa chains, or two macrocyclic ligands with a polyamine chain which are connecting the 2 and 9 positions of phenanthroline, have been determined by means of potentiometric measurements. The results are compared to those reported for other ligands with a similar molecular architecture. Of the complexes that contain phenanthroline in their macrocycle, the Cu(II) ion of the complex with the smallest and most rigid macrocycle (L3) has an unsaturated coordination sphere, while in the complex with the largest macrocycle (L5) the Cu(II) ion is coordinatively almost saturated. These results are corroborated by the crystal structure of the [CuL5](ClO4)2 complex. The affinity of the ligands and the complexes towards nucleic acids was studied by measuring the changes in the melting temperature, which showed that the affinity of the macrocyclic ligands towards double-stranded DNA or RNA is generally smaller than that of their linear analogues that bear a similar charge, with a strong preference for polyA-polyU, a model for RNA. However, the complexes of two of the changed macrocyclic ligands which contain a phenanthroline unit (L4, L5) showed a distinctly larger increase in their melting temperature deltaTm with DNA (polydA-polydT), which is reversed again in favor of RNA upon metallation to the dinuclear copper complex with L5. Experiments with supercoiled plasmid DNA showed a particularly effective cleavage with a mononuclear Cu(II) complex that contains a phenanthroline unit (L6). Related ligands showed less activity towards DNA, but not so towards the biocidic bis(p-nitrophenyl)phosphate (BNPP). In both cases (with DNA and BNPP) the activity seemed to increase with decrease of coordinative saturation of the Cu(II) ion, with the exception of one particular ligand (L6). Experiments with radical scavengers in the DNA experiments showed some decrease in cleavage, which indicates the participation of redox processes.
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Affiliation(s)
- D K Chand
- FR Organische Chemie, Universität des Saarlandes, Saarbrücken, Germany
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Secco F, Tinè M, Venturini M, Bencini A, Giorgi C, Valtancoli B. Equilibria and kinetics of complex formation between nickel(II) and the polyamine Me2octaen. Polyhedron 2000. [DOI: 10.1016/s0277-5387(00)00551-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Pontillon Y, Bencini A, Caneschi A, Dei A, Gatteschi D, Gillon B, Sangregorio C, Stride J, Totti F. Spin-Density Map of the Triplet Ground State of a Titanium(IV) Complex with Schiff-Base Diquinone Radical Ligands: An Investigation Using Polarized-Neutron Diffraction and Density-Functional Theory This work was supported by the 3MD EU network (contract ERB 4061 PL 97-0197). Angew Chem Int Ed Engl 2000; 39:1786-1788. [PMID: 10934361 DOI: 10.1002/(sici)1521-3773(20000515)39:10<1786::aid-anie1786>3.0.co;2-i] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Y Pontillon
- Dipartimento di Chimica Università degli Studi di Firenze Via Maragliano 77, 50144 Florence (Italy)
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49
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Bencini A, Bill E, Mariotti F, Totti F, Scozzafava A, Vargas A. Density functional description of the early stages of the dioxygenation of [(MeC(CH2PPh2)3)M(catecholate)]+ complexes [M = Co(III), Ir(III)]: toward a rationalization of the catalytic mechanism of ring-opening dioxygenases. Inorg Chem 2000; 39:1418-25. [PMID: 12526444 DOI: 10.1021/ic990633i] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Density Functional Theory (DFT) has been applied to characterize the early stages of the reaction of dioxygenation of [(triphos)M(catecholate)]+ complexes [M = Co(III), Ir(III); triphos = MeC(CH2PPh2)3], which have been considered to be models of ring-opening dioxygenases. The structural features of the starting complexes and of the intermediate complexes formed by addition of O2 to the coordinated catecholato ion are well reproduced. The calculations showed that this preliminary stage can be obtained only when the oxygen molecule attacks the molecule on the catecholato site.
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Affiliation(s)
- A Bencini
- Dipartimento di Chimica, Università di Firenze, Firenze, Italy. Max-Planck-Institut für Strahlenchemie, Mülheim, Germany
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50
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Bencini A, Ercolanelli R, Sbaragli A, Verrucchi C. Groundwaters of Florence (Italy): Trace element distribution and vulnerability of the aquifers. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf00767403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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