151
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Metal-Independent Pathways of Chlorinated Phenol/Quinone Toxicity. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/b978-0-444-53864-2.00001-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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152
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Simon A, Ballai C, Lente G, Fábián I. Structure–reactivity relationships and substituent effect additivity in the aqueous oxidation of chlorophenols by cerium(iv). NEW J CHEM 2011. [DOI: 10.1039/c0nj00529k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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153
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High-efficient photooxidative degradation of dyes catalyzed by hetero-nuclear complex under light irradiation. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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154
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Electrochemical catalysis and stability of tetraamido macrocyclic ligands iron immobilized on modified pyrolytic graphite electrode. Catal Today 2010. [DOI: 10.1016/j.cattod.2010.03.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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155
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Ellis WC, Tran CT, Roy R, Rusten M, Fischer A, Ryabov AD, Blumberg B, Collins TJ. Designing green oxidation catalysts for purifying environmental waters. J Am Chem Soc 2010; 132:9774-81. [PMID: 20565079 DOI: 10.1021/ja102524v] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe the synthesis, characterization, aqueous behavior, and catalytic activity of a new generation of Fe(III)-TAML (tetraamido macrocycle ligand) activators of peroxides (2), variants of [Fe{(OC)(2)(o,o'-NC(6)H(4)NCO)(2)CMe(2)}(OH(2))(-)] (2d), which have been designed to be especially suitable for purifying water of recalcitrant oxidizable pollutants. Activation of H(2)O(2) by 2 (k(I)) as a function of pH was analyzed via kinetic studies of Orange II bleaching. This was compared with the known behavior of the first generation of Fe(III)-TAMLs (1). Novel reactivity features impact the potential for oxidant activation for water purification by 2d and its aromatic ring-substituted dinitro (2e) and tetrachloro (2f) derivatives. Thus, the maximum activity for 2e occurs at pH 9, the closest yet to the EPA guidelines for drinking water (6.5-8.5), allowing 2e to rapidly activate H(2)O(2) at pH 7.7. In water, 2e has two axial water ligands with pK(a)'s of 8.4 and 10.0 (25 degrees C). The former is the lowest for all Fe(III)-TAMLs developed to date and is key to 2e's exceptional catalytic activity in neutral and slightly basic solutions. Below pH 7, 2d was found to be quite sensitive to demetalation in phosphate buffers. This was overcome by iterative design to give 2e (hydrolysis rate 2d > 100 x 2e). Mechanistic studies highlight 2e's increased stability by establishing that to demetalate 2e at a comparable rate to which H(2)PO(4)(-) demetalates 2d, H(3)PO(4) is required. A critical criterion for green catalysts for water purification is the avoidance of endocrine disruptors, which can impair aquatic life. Fe(III)-TAMLs do not alter transcription mediated by mammalian thyroid, androgen, or estrogen hormone receptors, suggesting that 2 do not bind to the receptors and reducing concerns that the catalysts might have endocrine disrupting activity.
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Affiliation(s)
- W Chadwick Ellis
- Department of Chemistry, Institute of Green Science, Mellon Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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156
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Detoxifying carcinogenic polyhalogenated quinones by hydroxamic acids via an unusual double Lossen rearrangement mechanism. Proc Natl Acad Sci U S A 2010; 107:20686-90. [PMID: 21076034 DOI: 10.1073/pnas.1010950107] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hydroxamic acids, which are best-known for their metal-chelating properties in biomedical research, have been found to effectively detoxify the carcinogenic polyhalogenated quinoid metabolites of pentachlorophenol and other persistent organic pollutants. However, the chemical mechanism underlying such detoxication is unclear. Here we show that benzohydroxamic acid (BHA) could dramatically accelerate the conversion of the highly toxic tetrachloro-1, 4-benzoquinone (p-chloranil) to the much less toxic 2,5-dichloro-3, 6-dihydroxy-1, 4-benzoquonine (chloranilic acid), with rate accelerations of up to 150,000-fold. In contrast, no enhancing effect was observed with O-methyl BHA. The major reaction product of BHA was isolated and identified as O-phenylcarbamyl benzohydroxamate. On the basis of these data and oxygen-18 isotope-labeling studies, we proposed that suicidal nucleophilic attack coupled with an unexpected double Lossen rearrangement reaction was responsible for this remarkable acceleration of the detoxication reaction. This is the first report of an unusually mild and facile Lossen-type rearrangement, which could take place under normal physiological conditions in two consecutive steps. Our findings may have broad biological and environmental implications for future research on hydroxamic acids and polyhalogenated quinoid carcinogens, which are two important classes of compounds of major biomedical and environmental interest.
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157
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Yadav V, Shitiz K, Pandey R, Yadav J. Chlorophenol stress affects aromatic amino acid biosynthesis-a genome-wide study. Yeast 2010; 28:81-91. [DOI: 10.1002/yea.1825] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 09/07/2010] [Indexed: 11/08/2022] Open
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158
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Tong GSM, Che C. Density Functional Theory Studies of [Fe(O)
2
L]
2+
: What is the Role of the Spectator Ligand L with Different Coordination Numbers? Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000656] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Glenna So Ming Tong
- Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for DrugDiscovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Chi‐Ming Che
- Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for DrugDiscovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong
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159
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Yin L, Niu J, Shen Z, Chen J. Mechanism of reductive decomposition of pentachlorophenol by Ti-doped beta-Bi(2)O(3) under visible light irradiation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:5581-5586. [PMID: 20583811 DOI: 10.1021/es101006s] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The reductive decomposition of pentachlorophenol (PCP) by photocatalysis with Ti-doped beta-Bi(2)O(3) was investigated under visible light (lambda > 420 nm) irradiation. The results indicated that hydroxyl radical (*OH) and singlet oxygen ((1)O(2)) could not be detected with electron spin resonance (ESR) on the photocatalyst under light irradiation. An electron scavenger weakened the photocatalytic activity of the photocatalyst for the decomposition of PCP; however, scavengers of reactive oxygen species (ROS) enhanced the activity. The decomposition intermediates of PCP detected by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) suggested the existence of phenol, cyclohexanone, cyclohexanol, glycol, and propylene. All the evidence suggested that reductive dechlorination was the major route in the decomposition of PCP, during which the photogenerated electron under visible light irradiation acted as reductant. The reliability of the proposed reductive mechanism was further verified by comparing the reduction potential (E(re)) of PCP with the conduction band potential (E(cb)) of the photocatalyst. The decomposition pathway of PCP with electron reduction under visible light irradiation was also investigated.
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Affiliation(s)
- Lifeng Yin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China
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160
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Christoforidis KC, Louloudi M, Deligiannakis Y. Substrate and co-catalyst effects on the local coordination environment of a Fe–porphyrin catalyst. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.06.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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161
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Ellis WC, Tran CT, Denardo MA, Fischer A, Ryabov AD, Collins TJ. Design of more powerful iron-TAML peroxidase enzyme mimics. J Am Chem Soc 2010; 131:18052-3. [PMID: 19928965 DOI: 10.1021/ja9086837] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Environmentally useful, small molecule mimics of the peroxidase enzymes must exhibit very high reactivity in water near neutral pH. Here we describe the design and structural and kinetic characterization of a second generation of iron(III)-TAML activators with unprecedented peroxidase-mimicking abilities. Iterative design has been used to remove the fluorine that led to the best performers in first-generation iron-TAMLs. The result is a superior catalyst that meets a green chemistry objective by being comprised exclusively of biochemically common elements. The rate constants for bleaching at pH 7, 9, and 11 of the model substrate, Orange II, shows that the new Fe(III)-TAML has the fastest reactivity at pH's closer to neutral of any TAML activator to date. Under appropriate conditions, the new catalyst can decolorize Orange II without loss of activity for at least 10 half-lives, attesting to its exceptional properties as an oxidizing enzyme mimic.
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Affiliation(s)
- W Chadwick Ellis
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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162
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163
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Synthesis, structures and photocatalytic properties of a mononuclear copper complex with pyridine-carboxylato ligands. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.01.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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164
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Banerjee D, Apollo FM, Ryabov AD, Collins TJ. The impact of surfactants on Fe(III)-TAML-catalyzed oxidations by peroxides: accelerations, decelerations, and loss of activity. Chemistry 2010; 15:10199-209. [PMID: 19711381 DOI: 10.1002/chem.200900729] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Iron(III) complexes of tetraamidato macrocyclic ligands (TAMLs), [Fe{4-XC(6)H(3)-1,2-(NCOCMe(2)NCO)(2)CR(2)}(OH(2))](-), 1 (1 a: X = H, R = Me; 1 b: X = COOH, R = Me); 1 c: X = CONH(CH(2))(2)COOH, R = Me; 1 d: CONH(CH(2))(2)NMe(2), R = Me; 1 e: X = CONH(CH(2))(2)NMe(3) (+), R = Me; 1 f: X = H, R = F), have been tested as catalysts for the oxidative decolorization of Orange II and Sudan III dyes by hydrogen peroxide and tert-butyl hydroperoxide in the presence of micelles that are neutral (Triton X-100), positively charged (cetyltrimethylammonium bromide, CTAB), and negatively charged (sodium dodecyl sulfate, SDS). The previously reported mechanism of catalysis involves the formation of an oxidized intermediate from 1 and ROOH (k(I)) followed by dye bleaching (k(II)). The micellar effects on k(I) and k(II) have been separately studied and analyzed by using the Berezin pseudophase model of micellar catalysis. The largest micellar acceleration in terms of k(I) occurs for the 1 a-tBuOOH-CTAB system. At pH 9.0-10.5 the rate constant k(I) increased by approximately five times with increasing CTAB concentration and then gradually decreased. There was no acceleration at higher pH, presumably owing to the deprotonation of the axial water ligand of 1 a in this pH range. The k(I) value was only slightly affected by SDS (in the oxidation of Orange II), but was strongly decelerated by Triton X-100. No oxidation of the water-insoluble, hydrophobic dye Sudan III was observed in the presence of the SDS micelles. The k(II) value was accelerated by cationic CTAB micelles when the hydrophobic primary oxidant tert-butyl hydroperoxide was used. It is hypothesized that tBuOOH may affect the CTAB micelles and increase the binding of the oxidized catalysts. The tBuOOH-CTAB combination accelerated both of the catalysis steps k(I) and k(II).
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Affiliation(s)
- Deboshri Banerjee
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
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165
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Tang J, Chen L, Sun J, Lv K, Deng K. Synthesis and properties of iron(II) tetra(1,4-dithiin)porphyrazine bearing peripheral long-chain alkyl group of active end-bromine. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2009.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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166
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Li Y, Yi Z, Zhang J, Wu M, Liu W, Duan P. Efficient degradation of Rhodamine B by using ethylenediamine-CuCl2 complex under alkaline conditions. JOURNAL OF HAZARDOUS MATERIALS 2009; 171:1172-1174. [PMID: 19683868 DOI: 10.1016/j.jhazmat.2009.06.096] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 06/09/2009] [Accepted: 06/18/2009] [Indexed: 05/28/2023]
Abstract
In this work, we have developed a simple and efficient approach to the degradation of organic dyes using ethylenediamine-CuCl(2) complex as the catalyst under basic conditions. Rhodamine B has been used as model compound and all experiments were carried out at normal atmospheric pressure and temperature (25+/-1 degrees C) under open-wide system. The different pH values from 7.0 to 14.0 and the catalyst recycling were investigated. The results indicated that ethylenediamine-CuCl(2) was an effective catalyst in the degradation of Rhodamine B at pH 7.0-12.0. It would provide a useful insight into the development of new routes in organic wastewater treatment.
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Affiliation(s)
- Ying Li
- Key Laboratory of Natural Pharmaceutical & Chemical Biology of Yunnan Province, Honghe University, Mengzi 661100, PR China
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167
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Su R, Sun J, Sun Y, Deng K, Cha D, Wang D. Oxidative degradation of dye pollutants over a broad pH range using hydrogen peroxide catalyzed by FePz(dtnCl2)4. CHEMOSPHERE 2009; 77:1146-1151. [PMID: 19818469 DOI: 10.1016/j.chemosphere.2009.08.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 08/03/2009] [Accepted: 08/03/2009] [Indexed: 05/28/2023]
Abstract
The oxidative degradation of rhodamine B (RhB) with hydrogen peroxide activated by iron(II) tetra-(5,6-dichloro-1,4-dithiin)-porphyrazine (abbreviated as FePz(dtnCl(2))(4)) was studied by means of UV-Vis spectra, GC-MS and TOC analysis, in which the effects of pH, light, concentration of hydrogen peroxide and the degraded products of the RhB were investigated. The results indicate that FePz(dtnCl(2))(4) was found to exhibit high catalytic activity to activate hydrogen peroxide for the oxidative degradation of RhB and good stability over a broad pH range under visible light irradiation (lambda>420 nm). The conversions of RhB in 80 min were 99%, 85%, 52% and the TOC removals in 240 min were 91%, 64%, 18% when the initial solutions pHs were 2, 7, 11, respectively. HO(.) radicals were testified to generate in the biomimetic catalytic system both at pH 2 and 7 by means of spin-trapping electron spin resonance. However, control experiment with scavenging of HO() radicals displayed the quite different results at pH 2 and 7. Based on experiment results together with theoretic deduction, a mechanism for RhB oxidation involving two kinds of reactive oxidizing species was proposed, the homolytic cleavage generating the HO(.) radicals and the heterolytic cleavage generating the Pz(.)(+)Fe(IV)=O radicals.
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Affiliation(s)
- Rong Su
- Key Laboratory of Catalysis and Materials Science, State Ethnic Affairs Commission and Ministry of Education, South-Central University for Nationalities, Wuhan 430073, PR China
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168
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Xu A, Xiong H, Yin G. Decolorization of Dye Pollutions by Manganese Complexes with Rigid Cross-Bridged Cyclam Ligands and Its Mechanistic Investigations. J Phys Chem A 2009; 113:12243-8. [DOI: 10.1021/jp9060335] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Aihua Xu
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hui Xiong
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Guochuan Yin
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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169
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Xia C, Liu Y, Zhou S, Yang C, Liu S, Xu J, Yu J, Chen J, Liang X. The Pd-catalyzed hydrodechlorination of chlorophenols in aqueous solutions under mild conditions: a promising approach to practical use in wastewater. JOURNAL OF HAZARDOUS MATERIALS 2009; 169:1029-1033. [PMID: 19477071 DOI: 10.1016/j.jhazmat.2009.04.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 04/13/2009] [Accepted: 04/14/2009] [Indexed: 05/27/2023]
Abstract
Catalytic hydrotreating of chlorophenols was carried out in water with Pd/C at 25 degrees C under atmospheric pressure. 1.0% (w/w) monocholophenols was completely dechlorinated within 60 min. Phenol, cyclohexanone and cyclohexanol were formed. In contrast to the dechlorination of monochlorophenols, the hydrogenation reaction of polychlorinated phenols became difficult and reaction rates were strongly dependent upon the number of the chlorine atoms. The solvent property had a considerably important influence on the dechlorination reaction. Water as a solvent showed more advantages than organic solvents. It was much easier to be hydrodechlorinated for chlorophenols in aqueous solutions. However, the presence of THF, dioxane, DMSO or DMF in water was disadvantageous to the reaction and easily to cause Pd/C deactivation. Additionally, when different halogenated organic compounds were present in aqueous solution, the dehalogenation reaction was the competitive hydrogenation process.
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Affiliation(s)
- Chuanhai Xia
- Yantai Institute of Coastal Zone Research for Sustainable Development, CAS, Yantai 264003, China.
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170
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Zhu BZ, Shan GQ. Potential mechanism for pentachlorophenol-induced carcinogenicity: a novel mechanism for metal-independent production of hydroxyl radicals. Chem Res Toxicol 2009; 22:969-77. [PMID: 19408893 DOI: 10.1021/tx900030v] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hydroxyl radical ((*)OH) has been considered to be one of the most reactive oxygen species produced in biological systems. It has been shown that (*)OH can cause DNA, protein, and lipid oxidation. One of the most widely accepted mechanisms for (*)OH production is through the transition metal-catalyzed Fenton reaction. Pentachlorophenol (PCP) was one of the most widely used biocides, primarily for wood preservation. PCP is now ubiquitously present in our environment and even found in people who are not occupationally exposed to it. PCP has been listed as a priority pollutant by the U.S. Environmental Protection Agency (EPA) and classified as a group 2B environmental carcinogen by the International Association for Research on Cancer (IARC). The genotoxicity of PCP has been attributed to its two major quinoid metabolites: tetrachlorohydroquinone and tetrachloro-1,4-benzoquinone (TCBQ). Although the redox cycling of PCP quinoid metabolites to generate reactive oxygen species is believed to play an important role, the exact molecular mechanism underlying PCP genotoxicity is not clear. Using the salicylate hydroxylation assay and electron spin resonance (ESR) secondary spin-trapping methods, we found that (*)OH can be produced by TCBQ and H(2)O(2) independent of transition metal ions. Further studies showed that TCBQ, but not its corresponding semiquinone radical, the tetrachlorosemiquinone radical (TCSQ(*)), is essential for (*)OH production. The major reaction product between TCBQ and H(2)O(2) was identified to be trichloro-hydroxy-1,4-benzoquinone (TrCBQ-OH), and H(2)O(2) was found to be the source and origin of the oxygen atom inserted into this reaction product. On the basis of these data, we propose that (*)OH production by TCBQ and H(2)O(2) is not through a semiquinone-dependent organic Fenton reaction but rather through the following novel mechanism: a nucleophilic attack of H(2)O(2) to TCBQ, leading to the formation of an unstable trichloro-hydroperoxyl-1,4-benzoquinone (TrCBQ-OOH) intermediate, which decomposes homolytically to produce (*)OH. These findings represent a novel mechanism of (*)OH formation not requiring the involvement of redox-active transition metal ions and may partly explain the potential carcinogenicity of the widely used biocides such as PCP and other polyhalogenated aromatic compounds.
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Affiliation(s)
- Ben-Zhan Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P. R. China.
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171
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Beach ES, Duran JL, Horwitz CP, Collins TJ. Activation of Hydrogen Peroxide by an Fe-TAML Complex in Strongly Alkaline Aqueous Solution: Homogeneous Oxidation Catalysis with Industrial Significance. Ind Eng Chem Res 2009. [DOI: 10.1021/ie9005723] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Evan S. Beach
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213
| | - Jennifer L. Duran
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213
| | - Colin P. Horwitz
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213
| | - Terrence J. Collins
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213
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172
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Poerschmann J, Trommler U. Pathways of advanced oxidation of phenol by Fenton's reagent—Identification of oxidative coupling intermediates by extractive acetylation. J Chromatogr A 2009; 1216:5570-9. [DOI: 10.1016/j.chroma.2009.05.075] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 05/15/2009] [Accepted: 05/25/2009] [Indexed: 10/20/2022]
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173
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Metal-independent decomposition of hydroperoxides by halogenated quinones: detection and identification of a quinone ketoxy radical. Proc Natl Acad Sci U S A 2009; 106:11466-71. [PMID: 19556549 DOI: 10.1073/pnas.0900065106] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have shown recently that halogenated quinones could enhance the decomposition of hydroperoxides and formation of alkoxyl/hydroxyl radicals through a metal-independent mechanism. However, neither the proposed quinone enoxy radical intermediate, nor the major reaction products were unambiguously identified. In the present study, one of the major reaction products between 2,5-dichloro-1,4-benzoquinone (DCBQ) and t-butylhydroperoxide (t-BuOOH) was isolated and purified by semipreparative HPLC, and identified as 2-hydroxy-3-t-butoxy-5-chloro-1,4-benzoquinone [CBQ(OH)-O-t-Bu], which is the rearranged isomer of the postulated quinone-peroxide reaction intermediate. The formation of CBQ(OH)-O-t-Bu was found to be inhibited by the spin trapping agent 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and concurrently, a new DMPO adduct with 1-chlorine isotope peak clusters at m/z 268 was observed. Further electron spin resonance (ESR) spin-trapping, (1)H-NMR and HPLC/Fourier transform ion cyclotron resonance (FTICR) mass spectrometric studies with oxygen-17-labeled and unlabeled hydrogen peroxide strongly suggest that the radical trapped by DMPO is a carbon-centered quinone ketoxy radical, which is the spin isomer of the proposed oxygen-centered quinone enoxy radical. Analogous results were observed when DCBQ was substituted by other halogenated quinones. This study represents the first detection and identification of an unusual carbon-centered quinone ketoxy radical, which provides direct experimental evidence to further support and expand our previously proposed mechanism for metal-independent decomposition of hydroperoxides by halogenated quinones.
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174
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Fallis IA, Griffiths PC, Cosgrove T, Dreiss CA, Govan N, Heenan RK, Holden I, Jenkins RL, Mitchell SJ, Notman S, Platts JA, Riches J, Tatchell T. Locus-Specific Microemulsion Catalysts for Sulfur Mustard (HD) Chemical Warfare Agent Decontamination. J Am Chem Soc 2009; 131:9746-55. [DOI: 10.1021/ja901872y] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ian A. Fallis
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Peter C. Griffiths
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Terence Cosgrove
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Cecile A. Dreiss
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Norman Govan
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Richard K. Heenan
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Ian Holden
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Robert L. Jenkins
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Stephen J. Mitchell
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Stuart Notman
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Jamie A. Platts
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - James Riches
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
| | - Thomas Tatchell
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, U.K., School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K., Department of Pharmacy, King’s College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NN, Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury SP4 0JQ, Wilts, U.K., and ISIS Pulsed Neutron & Muon Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, U.K
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175
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Chen S, Xu ZP, Zhang Q, Lu GM, Hao ZP, Liu S. Studies on adsorption of phenol and 4-nitrophenol on MgAl-mixed oxide derived from MgAl-layered double hydroxide. Sep Purif Technol 2009. [DOI: 10.1016/j.seppur.2009.03.016] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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176
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Evaluation of pathways involved in pentachlorophenol-induced apoptosis in rat neurons. Neurotoxicology 2009; 30:451-8. [DOI: 10.1016/j.neuro.2009.02.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 01/23/2009] [Accepted: 02/01/2009] [Indexed: 11/17/2022]
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177
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Gunschera J, Andersen JR, Schulz N, Salthammer T. Surface-catalysed reactions on pollutant-removing building products for indoor use. CHEMOSPHERE 2009; 75:476-482. [PMID: 19181362 DOI: 10.1016/j.chemosphere.2008.12.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 12/23/2008] [Accepted: 12/23/2008] [Indexed: 05/27/2023]
Abstract
In order to evaluate the potential for emission of secondary reaction products from building materials designed to remove pollutants from indoor air, four samples of ceiling tiles--three commercially available and one custom-made--were investigated in chamber experiments. The chambers were irradiated with artificial light simulating indoor conditions and formaldehyde as well as several VOCs (2-butanone, n-butanol, toluene, hexanal, n- butylacetate, 2-butoxyethanol, alpha-pinene, benzaldehyde, n-decane, limonene and 1,2-dichlorobenzene) were added. Depending on the individual substrate-substance combination, it was possible to identify secondary emissions, e.g. formaldehyde, furfural, acetophenone, n-butylbutyrate, n-butyl-i-butyrate, n-butylpropionate, 4-heptanone, acetic acid, i-butyraldehyde and crotonaldehyde. These were generated by cleavage, hydrolysis, rearrangement or radical reactions. Some of these reactions also occurred with samples not containing photocatalysts. All these secondary emissions have to be taken seriously into account when evaluating the performance of materials designed to remove pollutants from indoor air, as they can prove detrimental to human health.
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Affiliation(s)
- J Gunschera
- Fraunhofer Wilhelm-Klauditz-Institute Material Analysis and Indoor Chemistry, Bienroder Weg 54E, D-38108 Braunschweig, Germany.
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178
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Fe(III)-, Co(II)- and Ni(II)-impregnated MCM41 for wet oxidative destruction of 2,4-dichlorophenol in water. Catal Today 2009. [DOI: 10.1016/j.cattod.2008.03.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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179
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Li JM, Meng XG, Hu CW, Du J, Zeng XC. Oxidation of 4-chlorophenol catalyzed by Cu(II) complexes under mild conditions: Kinetics and mechanism. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcata.2008.10.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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180
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Ryabov AD, Collins TJ. Mechanistic considerations on the reactivity of green FeIII-TAML activators of peroxides. ADVANCES IN INORGANIC CHEMISTRY 2009. [DOI: 10.1016/s0898-8838(09)00208-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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181
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Ghosh A, Mitchell DA, Chanda A, Ryabov AD, Popescu DL, Upham EC, Collins GJ, Collins TJ. Catalase-peroxidase activity of iron(III)-TAML activators of hydrogen peroxide. J Am Chem Soc 2008; 130:15116-26. [PMID: 18928252 DOI: 10.1021/ja8043689] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Exceptionally high peroxidase-like and catalase-like activities of iron(III)-TAML activators of H 2O 2 ( 1: Tetra-Amidato-Macrocyclic-Ligand Fe (III) complexes [ F e{1,2-X 2C 6H 2-4,5-( NCOCMe 2 NCO) 2CR 2}(OH 2)] (-)) are reported from pH 6-12.4 and 25-45 degrees C. Oxidation of the cyclometalated 2-phenylpyridine organometallic complex, [Ru (II)( o-C 6H 4py)(phen) 2]PF 6 ( 2) or "ruthenium dye", occurs via the equation [ Ru II ] + 1/2 H 2 O 2 + H +-->(Fe III - TAML) [ Ru III ] + H 2 O, following a simple rate law rate = k obs (per)[ 1][H 2O 2], that is, the rate is independent of the concentration of 2 at all pHs and temperatures studied. The kinetics of the catalase-like activity (H 2 O 2 -->(Fe III - TAML) H 2 O + 1/2 O 2) obeys a similar rate law: rate = k obs (cat)[ 1][H 2O 2]). The rate constants, k obs (per) and k obs (cat), are strongly and similarly pH dependent, with a maximum around pH 10. Both bell-shaped pH profiles are quantitatively accounted for in terms of a common mechanism based on the known speciation of 1 and H 2O 2 in this pH range. Complexes 1 exist as axial diaqua species [FeL(H 2O) 2] (-) ( 1 aqua) which are deprotonated to afford [FeL(OH)(H 2O)] (2-) ( 1 OH) at pH 9-10. The pathways 1 aqua + H 2O 2 ( k 1), 1 OH + H 2O 2 ( k 2), and 1 OH + HO 2 (-) ( k 4) afford one or more oxidized Fe-TAML species that further rapidly oxidize the dye (peroxidase-like activity) or a second H 2O 2 molecule (catalase-like activity). This mechanism is supported by the observations that (i) the catalase-like activity of 1 is controllably retarded by addition of reducing agents into solution and (ii) second order kinetics in H 2O 2 has been observed when the rate of O 2 evolution was monitored in the presence of added reducing agents. The performances of the 1 complexes in catalyzing H 2O 2 oxidations are shown to compare favorably with the peroxidases further establishing Fe (III)-TAML activators as miniaturized enzyme replicas with the potential to greatly expand the technological utility of hydrogen peroxide.
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Affiliation(s)
- Anindya Ghosh
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA
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182
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Popescu DL, Chanda A, Stadler M, de Oliveira FT, Ryabov AD, Münck E, Bominaar EL, Collins TJ. High-valent first-row transition-metal complexes of tetraamido (4N) and diamidodialkoxido or diamidophenolato (2N/2O) ligands: Synthesis, structure, and magnetochemistry. Coord Chem Rev 2008. [DOI: 10.1016/j.ccr.2007.11.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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183
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Bruijnincx PCA, Viciano-Chumillas M, Lutz M, Spek AL, Reedijk J, van Koten G, Klein Gebbink RJM. Oxidative double dehalogenation of tetrachlorocatechol by a bio-inspired CuII complex: formation of chloranilic acid. Chemistry 2008; 14:5567-76. [PMID: 18449873 DOI: 10.1002/chem.200701878] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Copper(II) complexes of the potentially tripodal N,N,O ligand 3,3-bis(1-methylimidazol-2-yl)propionate (L1) and its conjugate acid HL1 have been synthesised and structurally and spectroscopically characterised. The reaction of equimolar amounts of ligand and CuII resulted in the complexes [Cu(L1)]n(X)n (X=OTf-, PF6(-); n=1,2), for which a new bridging coordination mode of L1 is inferred. Although these complexes showed moderate catecholase activity in the oxidation of 3,5-di-tert-butylcatechol, surprising reactivity with the pseudo-substrate tetrachlorocatechol was observed. A chloranilato-bridged dinuclear CuII complex was isolated from the reaction of [Cu(L1)]n(PF6)n with tetrachlorocatechol. This stoichiometric oxidative double dehalogenation of tetrachlorocatechol to chloranilic acid by a biomimetic copper(II) complex is unprecedented. The crystal structure of the product, [Cu2(ca)Cl2(HL1)2], shows a bridging bis-bidentate chloranilato (ca) ligand and ligand L1 coordinated as its conjugate acid (HL1) in a tridentate fashion. Magnetic susceptibility studies revealed weak antiferromagnetic coupling (J= -35 cm(-1)) between the two copper centres in the dinuclear complex. Dissolution of the green complex [Cu2(ca)Cl2(HL1)2] resulted in the formation of new pink-purple mononuclear compound [Cu(ca)(HL1)(H2O)], the crystal structure of which was determined. It showed a terminal bidentate chloranilato ligand and N,N-bidentate coordination of ligand HL1, which illustrates the flexible coordination chemistry of ligand L1.
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Affiliation(s)
- Pieter C A Bruijnincx
- Chemical Biology & Organic Chemistry, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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184
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Lykourinou V, Hanafy AI, da Silva GFZ, Bisht KS, Larsen RW, Livingston BT, Angerhofer A, Ming LJ. How Well Should the Active Site and the Specific Recognition Be Defined for Proficient Catalysis? – Effective and Cooperative Polyphenol/Catechol Oxidation and Oxidative DNA Cleavage by a Copper(II)-Binding and H-Bonding Copolymer. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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185
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Theodoridis A, Maigut J, Puchta R, Kudrik EV, van Eldik R. Novel iron(III) porphyrazine complex. Complex speciation and reactions with NO and H2O2. Inorg Chem 2008; 47:2994-3013. [PMID: 18351731 DOI: 10.1021/ic702041g] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The complex [iron(III) (octaphenylsulfonato)porphyrazine] (5-), Fe (III)(Pz), was synthesized. The p K a values of the axially coordinated water molecules were determined spectrophotometrically and found to be p K a 1 = 7.50 +/- 0.02 and p K a 2 = 11.16 +/- 0.06. The water exchange reaction studied by (17)O NMR as a function of the pH was fast at pH = 1, k ex = (9.8 +/- 0.6) x 10 (6) s (-1) at 25 degrees C, and too fast to be measured at pH = 10, whereas at pH = 13, no water exchange reaction occurred. The equilibrium between mono- and diaqua Fe (III)(Pz) complexes was studied at acidic pH as a function of the temperature and pressure. Complex-formation equilibria with different nucleophiles (Br (-) and pyrazole) were studied in order to distinguish between a five- (in the case of Br (-)) or six-coordinate (in the case of pyrazole) iron(III) center. The kinetics of the reaction of Fe (III)(Pz) with NO was studied as a model ligand substitution reaction at various pH values. The mechanism observed is analogous to the one observed for iron(III) porphyrins and follows an I d mechanism. The product is (Pz)Fe (II)NO (+), and subsequent reductive nitrosylation usually takes place when other nucleophiles like OH (-) or buffer ions are present in solution. Fe (III)(Pz) also activates hydrogen peroxide. Kinetic data for the direct reaction of hydrogen peroxide with the complex clearly indicate the occurrence of more than one reaction step. Kinetic data for the catalytic decomposition of the dye Orange II by H 2O 2 in the presence of Fe (III)(Pz) imply that a catalytic oxidation cycle is initiated. The peroxide molecule first coordinates to the iron(III) center to produce the active catalytic species, which immediately oxidizes the substrate. The influence of the catalyst, oxidant, and substrate concentrations on the reaction rate was studied in detail as a function of the pH. The rate increases with increasing catalyst and peroxide concentrations but decreases with increasing substrate concentration. At low pH, the oxidation of the substrate is not complete because of catalyst decomposition. The observed kinetic traces at pH = 10 and 12 for the catalytic cycle could be simulated on the basis of the obtained kinetic data and the proposed reaction cycle. The experimental results are in good agreement with the simulated ones.
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Affiliation(s)
- Alexander Theodoridis
- Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstrasse 1, Erlangen, Germany
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186
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Chaliha S, Bhattacharyya KG. Wet oxidative method for removal of 2,4,6-trichlorophenol in water using Fe(III), Co(II), Ni(II) supported MCM41 catalysts. JOURNAL OF HAZARDOUS MATERIALS 2008; 150:728-36. [PMID: 17574332 DOI: 10.1016/j.jhazmat.2007.05.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2007] [Revised: 05/07/2007] [Accepted: 05/08/2007] [Indexed: 05/15/2023]
Abstract
Chlorophenols in water are resistant to biological oxidation and they have to be destroyed by chemical oxidation. In the present work, Fe(III), Co(II) and Ni(II) incorporated MCM41 mesoporous solids were used as catalysts for oxidation of 2,4,6-trichlorophenol in water with or without the oxidant, H(2)O(2). The catalysts were prepared by impregnation and were characterized by XRD and FTIR measurements. The parent MCM41, Fe(III), Co(II) and Ni(II) impregnated MCM41 had cation exchange capacity of 20.5, 25.5, 24.2, 26.0 mequiv./100g, respectively. The catalysts were used after calcination at 773-873 K for 5 h. The reactions were carried out in a high pressure stirred reactor at 0.2 MPa (autogenous) and 353 K under various reaction conditions. The conversion achieved with Fe(III), Co(II) and Ni(II) incorporated MCM41 in 5h is respectively 59.4, 50.0 and 65.6% with 2,4,6-TCP:H(2)O(2) molar ratio of 1:1, and 60.2, 60.9 and 68.8% in absence of H(2)O(2). The oxidation has a first order rate coefficient of (1.2-4.8)x10(-3)min(-1). The results show that introduction of Fe(III), Co(II) and Ni(II) into MCM-41 through impregnation produces very effective catalysts for wet oxidation of 2,4,6-trichlorophenol.
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Affiliation(s)
- Suranjana Chaliha
- Department of Chemistry, Gauhati University, Guwahati 781014, Assam, India
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187
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Chaliha S, Bhattacharyya KG. Using Mn(II)−MCM41 as an Environment-Friendly Catalyst to Oxidize Phenol, 2-Chlorophenol, and 2-Nitrophenol in Aqueous Solution. Ind Eng Chem Res 2008. [DOI: 10.1021/ie071075f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Suranjana Chaliha
- Department of Chemistry, Gauhati University, Guwahati 781014, Assam, India
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188
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Tao X, Su J, Wang L, Chen JF. A new heterogeneous catalytic system for wastewater treatment: Fe-immobilized polyelectrolyte microshells for accumulation and visible light-assisted photooxidative degradation of dye pollutants. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.molcata.2007.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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189
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Bruijnincx PCA, van Koten G, Klein Gebbink RJM. Mononuclear non-heme iron enzymes with the 2-His-1-carboxylate facial triad: recent developments in enzymology and modeling studies. Chem Soc Rev 2008; 37:2716-44. [DOI: 10.1039/b707179p] [Citation(s) in RCA: 412] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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190
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Huber SG, Kilian G, Scholer HF. Carbon suboxide, a highly reactive intermediate from the abiotic degradation of aromatic compounds in soil. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:7802-7806. [PMID: 18075091 DOI: 10.1021/es071530z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The formation of volatile compounds during abiotic degradation processes of aromatic compounds in soil has been the subject of many experimental studies but should be examined further. In this context, the present work investigates the natural formation of carbon suboxide using the model compounds catechol and 3,5-dichlorocatechol and also a soil sample from a peat bog. The measurements were performed with a purge and trap GC/ MS system following various optimization steps. Under certain conditions, we obtained 16.7 ng of carbon suboxide from a 250 mg soil sample. We also found that the formation of carbon suboxide requires a definite activation energy and that it is rather short-lived in the natural environment. A subsequent reaction to malonic acid is expected in the presence of water. It is shown that iron-(III), hydrogen peroxide, and chloride are prerequisites for its formation. Experimental parameters for the highest yield of carbon suboxide depend on the precise molecular structure of the model compound or on the individual soil sample, respectively. The presented results point to a new degradation process for aromatic compounds in soil.
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Affiliation(s)
- Stefan G Huber
- Institute of Environmental Geochemistry, University of Heidelberg, Im Neuenheimer Feld 236, 69120 Heidelberg, Germany.
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191
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Chen W, Lu W, Yao Y, Xu M. Highly efficient decomposition of organic dyes by aqueous-fiber phase transfer and in situ catalytic oxidation using fiber-supported cobalt phthalocyanine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:6240-6245. [PMID: 17937309 DOI: 10.1021/es070002k] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A novel metallophthalocyanine derivative, cobalt tetra (2,4-dichloro-1,3,5-triazine) aminophthalocyanine (Co-TDTAPc), was prepared and immobilized on cellulosic fiber by covalent bond to obtain a supported oxidation catalyst (Co-TDTAPc-F). Co-TDTAPc-F/H202 system based on phase-transfer catalytic oxidation for decomposing dyes, including acid, reactive, and direct dyes, has been investigated thoroughly. Compared to traditional adsorption technologies and advanced oxidation processes (AOPs) for dye treatment, Co-TDTAPc-F/H202 combines the advantages of both and is more efficient and more effective. Azo dyes such as C. I. Acid Red 1 (AR1) can be quickly adsorbed onto/into the fiber from aqueous solution and decomposed in situ simultaneously in the presence of Co-TDTAPc-F and H2O2. It has been found that the reaction process is not affected by the visible light. Furthermore, it turns the negative effect of NaCl normally observed in homogeneous catalysis into positive one. The catalytic reaction can proceed at a wide pH range from acidic to alkaline. In 60 min, more than 98% of AR1 was eliminated at initial pH 2. In 90 min, about 40% of the carbon was found mineralized as determined by the analysis of the residual total organic carbon. The high-performance liquid chromatography result indicated that a substantial amount of the starting AR1 was converted to other organic products, while gas chromatography/mass spectrometry analysis showed the rest of the carbon existed mainly as small molecular biodegradable aliphatic carboxylic compounds such as oxalic acid, malonic acid, and maleic acid, etc. Co-TDTAPc-F is stable, causes no secondary pollution, and remains efficient in repetitive test cycles with no obvious degradation of catalytic activity.
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Affiliation(s)
- Wenxing Chen
- Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education of China, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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192
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Ji H, Song W, Chen C, Yuan H, Ma W, Zhao J. Anchored oxygen-donor coordination to iron for photodegradation of organic pollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:5103-7. [PMID: 17711230 DOI: 10.1021/es070021u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A photocatalyst of oxygen-donor coordination to iron, complex of 5-sulfosalicylic acid (SSA) with ferric ion, supported on resin to cycle Fe3+/Fe2+ center under visible irradiation can effectively generate *OH radicals from H2O2, leading to degradation of organic pollutants in water. The higher turnover number was achieved by this catalyst for the degradation of model compound than those reported for the general N-donor ligands catalysts. The reversible "on/ off" switching of Fe3+/Fe2+ complexation with SSA, coupled with the phenol/phenoxyl radical conversion of the o-phenoxyl moiety of SSA, produces an ideal catalytic system that separates the Fenton reaction and the followed oxidations by *OH radicals (in water phase) from the regeneration of the catalytic species, Fe (SSA)2-, which occurs on the surface of resin. This system not only inhibits the undesired destruction of the ligands by *OH radicals, improving the stability of the catalyst, but also avoids the unnecessary decomposition of H2O2 into HO2* that occurs in the homogeneous Fenton system. Therefore, the system suggests an efficient utilization of H2O2 for degradation of organic pollutants.
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Affiliation(s)
- Hongwei Ji
- Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, The Chinese Academy of Science, Beijing 100080, China
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193
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Sun J, Sun Y, Deng K, Hou H, Wang D. Oxidative Degradation of Organic Pollutants by Hydrogen Peroxide in the Presence of FePz(dtnCl2)4under Visible Irradiation. CHEM LETT 2007. [DOI: 10.1246/cl.2007.586] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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194
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Liao CJ, Chung TL, Chen WL, Kuo SL. Treatment of pentachlorophenol-contaminated soil using nano-scale zero-valent iron with hydrogen peroxide. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2006.09.050] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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195
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Chanda A, Ryabov AD, Mondal S, Alexandrova L, Ghosh A, Hangun-Balkir Y, Horwitz CP, Collins TJ. Activity-stability parameterization of homogeneous green oxidation catalysts. Chemistry 2007; 12:9336-45. [PMID: 17029311 DOI: 10.1002/chem.200600630] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Small-molecule synthetic homogeneous-oxidation catalysts are normally poorly protected from self-destruction under operating conditions. Achieving design control over both activity and half-life is important not only in advancing the utility of oxidation catalysts, but also in minimizing hazards associated with their use and disposal. Iron(III)-TAML (tetraamido-macrocyclic ligand) oxidant catalysts rapidly activate H(2)O(2) for numerous significant processes, exhibiting high and differing activity and varying half-lives depending upon the TAML design. A general approach is presented that allows for the simultaneous determination of the second-order rate constant for the oxidation of a targeted substrate by the active catalyst (k(II)) and the rate constant for the intramolecular self-inactivation of the active catalyst (k(i)). The approach is valid if the formation of the active catalyst from its resting state and the primary oxidizing agent, measured by the second-order rate constant k(I), is fast and the catalyst concentration is very low, such that bimolecular inactivation pathways can be neglected. If the oxidation process is monitored spectrophotometrically and is set up to be incomplete, the kinetic trace can be analyzed by using the equation ln(lnA(t))/A(infnity)=ln(k(II)/k(i)[Fe(III)](tot)-k(i)t, from which k(II) and k(i) can be determined. Here, A(t) and A(infinity) are absorbances at time t and at the end of reaction (t=infinity), respectively, and [Fe(III)](tot) is the total catalyst concentration. Several tools were applied to examine the validity of the approach by using a variety of different Fe(III)-TAML catalysts, H(2)O(2) and tBuOOH as oxidizing agents, and the dyes safranine O and orange II as target substrates. Learning how catalyst activities (k(II)) and catalyst half-lives (k(i)) can be controlled by ligand design is an important step in creating green catalysts that will not persist in the environment after they have achieved their purpose.
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Affiliation(s)
- Arani Chanda
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
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196
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Lente G, Fábián I. Kinetics and mechanism of the oxidation of water soluble porphyrin FeIIITPPS with hydrogen peroxide and the peroxomonosulfate ion. Dalton Trans 2007:4268-75. [PMID: 17893816 DOI: 10.1039/b708961a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The overall six-electron oxidation of water soluble porphyrin Fe(III)TPPS by hydrogen peroxide and peroxomonosulfate ion was studied by the stopped-flow method with UV-vis detection. A three-step consecutive reaction was observed with two intermediates: Fe(III)TPPS --> Int(1)--> Int(2)--> products. The products were identified as the iron(iii) complex of the biliverdin analog formed from TPPS and 4-sulfobenzoic acid. All the rate constants with both oxidizing agents were determined. Intermediate Int(1) is proposed to be the species (TPPS (+))Fe(IV)=O. Although no unambiguous proposal for the structure of Int(2) can be made, it is most probably the product of the four-electron oxidation of the original Fe(III)TPPS, contains an iron-oxo center and has a dissociable proton with a pK of around 3.1. In spite of the protolytic equilibria occuring in the pH region 2-4, the kinetic observations do not show pH dependence.
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Affiliation(s)
- Gábor Lente
- University of Debrecen, Department of Inorganic and Analytical Chemistry, Debrecen 10, P.O.B. 21, Hungary, H-4010.
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197
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Tiago de Oliveira F, Chanda A, Banerjee D, Shan X, Mondal S, Que L, Bominaar EL, Münck E, Collins TJ. Chemical and spectroscopic evidence for an FeV-oxo complex. Science 2006; 315:835-8. [PMID: 17185561 DOI: 10.1126/science.1133417] [Citation(s) in RCA: 353] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Iron(V)-oxo species have been proposed as key reactive intermediates in the catalysis of oxygen-activating enzymes and synthetic catalysts. Here, we report the synthesis of [Fe(TAML)(O)]- in nearly quantitative yield, where TAML is a macrocyclic tetraamide ligand. Mass spectrometry, Mössbauer, electron paramagnetic resonance, and x-ray absorption spectroscopies, as well as reactivity studies and density functional theory calculations show that this long-lived (hours at -60 degrees C) intermediate is a spin S = 1/2 iron(V)-oxo complex. Iron-TAML systems have proven to be efficient catalysts in the decomposition of numerous pollutants by hydrogen peroxide, and the species we characterized is a likely reactive intermediate in these reactions.
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198
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Mondal S, Hangun-Balkir Y, Alexandrova L, Link D, Howard B, Zandhuis P, Cugini A, Horwitz CP, Collins TJ. Oxidation of sulfur components in diesel fuel using Fe-TAML® catalysts and hydrogen peroxide. Catal Today 2006. [DOI: 10.1016/j.cattod.2006.06.025] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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199
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200
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Banerjee D, Markley AL, Yano T, Ghosh A, Berget PB, Minkley EG, Khetan SK, Collins TJ. “Green” Oxidation Catalysis for Rapid Deactivation of Bacterial Spores. Angew Chem Int Ed Engl 2006; 45:3974-7. [PMID: 16673442 DOI: 10.1002/anie.200504511] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Deboshri Banerjee
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA.
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