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Novoa-Ramírez CS, Silva-Becerril A, González-Ballesteros MM, Gomez-Vidal V, Flores-Álamo M, Ortiz-Frade L, Gracia-Mora J, Ruiz-Azuara L. Biological activity of mixed chelate copper(II) complexes, with substituted diimine and tridentate Schiff bases (NNO) and their hydrogenated derivatives as secondary ligands: Casiopeína's fourth generation. J Inorg Biochem 2023; 242:112097. [PMID: 36812707 DOI: 10.1016/j.jinorgbio.2022.112097] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/29/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022]
Abstract
We synthesize and characterize nine copper(II) compounds. Four with general formula [Cu(NNO)(NO3)] and five mixed chelates [Cu(NNO)(N-N)]+, where NNO corresponds to asymmetric salen ligands (E)-2-((2-(methylamino)ethylimino)methyl)phenolate (L1) and (E)-3-((2-(methylamino)ethylimino)methyl)naphthalenolate (LN1); and their hydrogenated derivatives 2-((2-(methylamino)ethylamino)methyl)phenolate (LH1) and 3-((2-(methylamino)ethylamino)methyl)naphthalenolate (LNH1); and N-N correspond to 4,4'-dimethyl-2,2'-bipiridyne(dmbpy) or 1,10-phenanthroline (phen). Using EPR, the geometries of the compounds in solution in DMSO were assigned, [Cu(LN1)(NO3)] and [Cu(LNH1)(NO3)] a square-planar, [Cu(L1)(NO3)], [Cu(LH1)(NO3)], [Cu(L1)(dmby)]+ and [Cu(LH1)(dmby)]+ a square-based pyramid; and [Cu(LN1)(dmby)]+, [Cu(LNH1)(dmby)]+ and [Cu(L1)(phen)]+ and elongated octahedral. By X-ray it was observed that [Cu(L1)(dmby)]+ and. [Cu(LN1)(dmby)]+ presented a square-based pyramidal, and [Cu(LN1)(NO3)]+ a square-planar geometry. The electrochemical study showed that copper reduction process is a quasi-reversible system, where the complexes with hydrogenated ligands were less oxidizing. The cytotoxicity of the complexes was tested by MTT assay, all the compounds showed biological activity in HeLa cell line, the mixed compounds were the more active ones. Naphthalene moiety, imine hydrogenation and aromatic diimine coordination, increased biological activity. A structure-activity relationships were found: Log(IC50) = - 1.01(Epc) - 0.35(Conjugated Rings) + 0.87, for Schiff base complexes and Log(IC50) = 0.078(Epc) - 0.32(Conjugated Rings) + 1.94, for hydrogenated complexes; the less oxidizing species with a great number of conjugated rings presented the best biological activity. Complexes-DNA binding constants were obtained by uv-vis studies using CT-DNA, the results suggested that the complexes can interact through the grooves, except the phenanthroline mixed complex that intercalate with DNA. Gel electrophoresis study with pBR 322 showed that compounds can produce changes in the form of DNA and some complexes can cleave DNA in the presence of H2O2.
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Affiliation(s)
- Cynthia Sinai Novoa-Ramírez
- Departamento de Química Inorgánica y Nuclear, Facultad de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, 04510 Ciudad de México, Mexico
| | - Areli Silva-Becerril
- Instituto de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, 04510 Ciudad de México, Mexico
| | - Mauricio Misael González-Ballesteros
- Departamento de Química Inorgánica y Nuclear, Facultad de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, 04510 Ciudad de México, Mexico
| | - Virginia Gomez-Vidal
- Instituto de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, 04510 Ciudad de México, Mexico
| | - Marcos Flores-Álamo
- Unidad de Servicios de Apoyo a la Investigación y a la Industria, Facultad de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, 04510 Ciudad de México, Mexico
| | - Luis Ortiz-Frade
- Departamento de Electroquímica, Centro de Investigación y Desarrollo Tecnológico en Electroquímica S.C. Parque Tecnológico, Sanfandila, Pedro de Escobedo, 76703 Querétaro, Mexico
| | - Jesús Gracia-Mora
- Departamento de Química Inorgánica y Nuclear, Facultad de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, 04510 Ciudad de México, Mexico
| | - Lena Ruiz-Azuara
- Departamento de Química Inorgánica y Nuclear, Facultad de Química, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, 04510 Ciudad de México, Mexico.
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Impact of toluene contamination on the oxygen reduction at polycrystalline platinum electrode: Poisoning and mitigation. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Chen J, Yang H, Fu H, He H, Zeng Q, Li X. Electrochemical oxidation mechanisms for selective products due to C-O and C-C cleavages of β-O-4 linkages in lignin model compounds. Phys Chem Chem Phys 2020; 22:11508-11518. [PMID: 32393942 DOI: 10.1039/d0cp01091j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Electrochemical oxidation is a promising and effective method for lignin depolymerization owing to its selective oxidation capacity and environmental friendliness. Herein, the electrooxidation of non-phenolic alkyl aryl ether monomers and β-O-4 dimers was experimentally (by cyclic voltammetry, in situ spectroelectrochemistry, and gas chromatography-mass spectroscopy) and theoretically (by DFT calculations) explored in detail. Compared to the reported literature (T. Shiraishi, T. Takano, H. Kamitakahara and F. Nakatsubo, Holzforschung, 2012, 66(3), 303-309), 1-(4-ethoxyphenyl)ethanol showed a distinguishable oxidation pathway, where the resulting carbonyl product surprisingly underwent a bond cleavage on alkyl-aryl ether to ultimately produce a quinoid like compound. In contrast, β-O-4 dimers, like 2-phenoxy-1-phenethanol and 2-phenoxyacetophenone also demonstrated electrochemical oxidation induced by Cβ-O and Cα-Cβ bond cleavages. For the oxidation products, the presence of the Cα-hydroxyl group in dimers was the key to selectively generate aldehyde-containing species under mild electrochemical conditions, otherwise it produces alcohol-containing products following a different mechanism compared to the Cα[double bond, length as m-dash]O containing dimers.
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Affiliation(s)
- Jing Chen
- School of Chemistry and Chemical Engineering, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, Guangdong, 510640, China.
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Miyabayashi K, Ishihara K, Joshi P, Shen Z, Miyake M. Aromatic Ring Size Effect of a Surface Modification Agent on Platinum Nanoparticle Electrocatalysts for Oxygen Reduction Reaction. Electrocatalysis (N Y) 2018. [DOI: 10.1007/s12678-018-0462-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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6
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Matanovic I, Chung HT, Kim YS. Benzene Adsorption: A Significant Inhibitor for the Hydrogen Oxidation Reaction in Alkaline Conditions. J Phys Chem Lett 2017; 8:4918-4924. [PMID: 28945382 DOI: 10.1021/acs.jpclett.7b02228] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Slow hydrogen oxidation reaction (HOR) kinetics on Pt under alkaline conditions is a significant technical barrier for the development of high-performance hydroxide exchange membrane fuel cells. Here we report that benzene adsorption on Pt is a major factor responsible for the sluggish HOR. Furthermore, we demonstrate that bimetallic catalysts, such as PtMo/C, PtNi/C, and PtRu/C, can reduce the adsorption of benzene and thereby improve HOR activity. In particular, the HOR voltammogram of PtRu/C in 0.1 M benzyl ammonium showed minimal benzene adsorption. Density functional theory calculations indicate that the adsorption of benzyl ammonium on the bimetallic PtRu is endergonic for all four possible orientations of the cation, which explains the significantly better HOR activity observed for the bimetallic catalysts. The new HOR inhibition mechanism described here provides insights for the design of future polymer electrolytes and electrocatalysts for better-performing polymer membrane-based fuel cells.
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Affiliation(s)
- Ivana Matanovic
- Department of Chemical and Biological Engineering, University of New Mexico , Albuquerque, New Mexico 87231 United States
- T-1: Physics and Chemistry of Materials, Los Alamos National Laboratory , Los Alamos, New Mexico 87545 United States
| | - Hoon Taek Chung
- MPA-11: Materials Synthesis and Integrated Devices, Los Alamos National Laboratory , Los Alamos, New Mexico 87545 United States
| | - Yu Seung Kim
- MPA-11: Materials Synthesis and Integrated Devices, Los Alamos National Laboratory , Los Alamos, New Mexico 87545 United States
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Kronawitter CX, Chen Z, Zhao P, Yang X, Koel BE. Electrocatalytic hydrogenation of pyridinium enabled by surface proton transfer reactions. Catal Sci Technol 2017. [DOI: 10.1039/c6cy02487d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is observed for the first time that pyridinium is hydrogenated at Pt electrodes in electrochemical conditions consistent with those previously shown to yield selective reduction of carbon dioxide to methanol and formic acid.
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Affiliation(s)
- C. X. Kronawitter
- Department of Chemical and Biological Engineering
- Princeton University
- Princeton
- USA
| | - Z. Chen
- Department of Chemical and Biological Engineering
- Princeton University
- Princeton
- USA
| | - P. Zhao
- Department of Chemistry
- Princeton University
- Princeton
- USA
| | - X. Yang
- Department of Chemical and Biological Engineering
- Princeton University
- Princeton
- USA
| | - B. E. Koel
- Department of Chemical and Biological Engineering
- Princeton University
- Princeton
- USA
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Gul T, Bischoff R, Permentier HP. Mechanism of aromatic hydroxylation of lidocaine at a Pt electrode under acidic conditions. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.12.089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sun R, Yang L, Zhang Y, Chu F, Wang G, Lv Y, Chen K. Novel synthesis of AB-type carbonated hydroxyapatite hierarchical microstructures with sustained drug delivery properties. CrystEngComm 2016. [DOI: 10.1039/c6ce01494a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Membrane Electrolysis of Toluene Hydrogenation with Water Decomposition for Energy Carrier Synthesis. Electrocatalysis (N Y) 2015. [DOI: 10.1007/s12678-015-0289-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Lu JJ, Ma JQ, Yi JM, Shen ZL, Zhong YJ, Ma CA, Li MC. Electrochemical Polymerization of Pyrrole Containing TEMPO Side Chain on Pt Electrode and Its Electrochemical Activity. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.03.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Electrochemical and In Situ FTIR Study of o-Cresol on Platinum Electrode in Acid Medium. Electrocatalysis (N Y) 2014. [DOI: 10.1007/s12678-013-0182-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Apodaca DC, Pernites RB, Del Mundo FR, Advincula RC. Detection of 2,4-dinitrotoluene (DNT) as a model system for nitroaromatic compounds via molecularly imprinted short-alkyl-chain SAMs. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:6768-6779. [PMID: 21534549 DOI: 10.1021/la105128q] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A 2-D molecularly imprinted monolayer (2-D MIM) approach was used to prepare a simple and robust sensor for nitroaromatic compounds with 2,4-dinitrotoluene (DNT) as the model compound, which is a precursor and analog for explosive 2,4,6-trinitrotoluene (TNT). In contrast to studies utilizing long-chain hexadecylmercaptan self-assembled monolayers (SAM)s for sensing, a shorter-chain alkylthiol (i.e., butanethiol SAM) was utilized for DNT detection. The role of the chain length of the coadsorbed alkylthiol was emphasized with a matched template during solution adsorption. Semiempirical PM3 quantum calculations were used to determine the molecular conformation and complexation of the adsorbates. A switching mechanism was invoked on the basis of the ability of the template analyte to alter the packing arrangement of the alkylthiol SAMs near defect sites as influenced by the DNT-ethanol solvent complex. A 2-D MIM was formed on the Au surface electrode of a quartz crystal microbalance (QCM), which was then used to sense various concentrations of the analyte. Interestingly, the 2-D MIM QCM also enabled the selective detection of DNT even in a mixed solution of competing molecules, demonstrating the selectivity figure of merit. Likewise, electrochemical impedance spectroscopy (EIS) data at different concentrations of DNT confirmed the 2-D MIM effectiveness for sensing based on the interfacial conformation and electron-transport properties of the imprinted butanethiol SAM.
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Affiliation(s)
- Dahlia C Apodaca
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
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Pei J, Qin S, Li GY, Hu CW. Water-promoted One-step Anodic Acetoxylation of Benzene to Phenyl Acetate with High Selectivity. CHINESE J CHEM PHYS 2011. [DOI: 10.1088/1674-0068/24/02/244-248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Cyclic-voltammetry behavior of Pt(111) in aqueous HClO4+C6H6: Influence of C6H6 concentration, scan rate and temperature. J Electroanal Chem (Lausanne) 2010. [DOI: 10.1016/j.jelechem.2010.04.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Kortsdottir K, Lindström RW, Åkermark T, Lindbergh G. Influence of toluene contamination at the hydrogen Pt/C anode in a proton exchange membrane fuel cell. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2009.11.048] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Lei Y, Zhao G, Zhang Y, Liu M, Liu L, Lv B, Gao J. Highly efficient and mild electrochemical incineration: mechanism and kinetic process of refractory aromatic hydrocarbon pollutants on superhydrophobic PbO₂ anode. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:7921-7927. [PMID: 20843064 DOI: 10.1021/es101693h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Aqueous aromatic hydrocarbons are chemically stable, high toxic refractory pollutants that can only be oxidized to phenols and quinone on either Pt or traditional PbO(2) electrodes. In this study, a novel method for the electrochemical incineration of benzene homologues on superhydrophobic PbO(2) electrode (hydrophobic-PbO(2)) was proposed under mild conditions. Hydrophobic-PbO(2) can achieve the complete mineralization of aromatic hydrocarbons and exhibit high removal effect, rapid oxidation rate, and low energy consumption. The kinetics of the electrochemical incineration was also investigated, and the results revealed that the cleavage of the benzene ring is a key factor affecting the incineration efficiency. Moreover, on hydrophobic-PbO(2), the decay of intermediates was rapid, and low concentrations of aromatics were accumulated during the reaction. The removal of the initial pollutants and the effects of oxidative cleavage were related to the number of methyl groups on the benzene ring. Specifically, the results of physical experiments and quantum calculations revealed that the charge density of carbon atoms increases with an increase in the number of methyl groups, which promotes the electrophilic attack of ·OH.
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Affiliation(s)
- Yanzhu Lei
- Department of Chemistry, Tongji University, 1239 Siping Road, 200092 Shanghai, China
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18
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Glycolate adsorption at gold and platinum electrodes: A theoretical and in situ spectroelectrochemical study. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2009.11.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Musilová-Kebrlová N, Janderka P, Trnková L. Electrochemical processes of adsorbed chlorobenzene and fluorobenzene on a platinum polycrystalline electrode. ACTA ACUST UNITED AC 2009. [DOI: 10.1135/cccc2008221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The electrode processes of chlorobenzene (CB) and fluorobenzene (FB) on polycrystalline platinum (Pt-pc) electrode in sulfuric acid were studied by differential electrochemical mass spectrometry (DEMS). Contrary to the oxidation of adsorbed benzene on Pt surface, the oxidation of adsorbed CB and FB in the oxygen adsorption region does not provide solely CO2 as the final product. At negative polarization potentials CB and FB were desorbed under dehalogenation. While in the case of FB only benzene was detected, CB gave intermediates besides benzene. The final product of stepwise hydrogenation of these species was cyclohexane.
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Kornienko VL, Chaenko NV, Kornienko GV. Indirect electrochemical destructive oxidation of aromatic compounds with reactive oxygen species. RUSS J ELECTROCHEM+ 2007. [DOI: 10.1134/s1023193507110043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Oliveira RTS, Salazar-Banda GR, Santos MC, Calegaro ML, Miwa DW, Machado SAS, Avaca LA. Electrochemical oxidation of benzene on boron-doped diamond electrodes. CHEMOSPHERE 2007; 66:2152-8. [PMID: 17126378 DOI: 10.1016/j.chemosphere.2006.09.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 09/12/2006] [Accepted: 09/12/2006] [Indexed: 05/12/2023]
Abstract
This work presents an electrochemical investigation of the benzene oxidation process in aqueous solution on boron-doped diamond (BDD) electrodes. Additionally, in order to determine the main products generated during the oxidation process, electrolysis and high performance liquid chromatography experiments were carried out. The complete degradation of this compound was performed aiming to a further application in waste water treatment. The cyclic voltammetry studies indicate that benzene is irreversibly oxidized in acid medium (H2SO4 0.5 M) on the BDD electrode surface at 2.0 V versus Ag/AgCl in a diffusion controlled process. During the cycling, other products are generated, and a pair of peaks was observed that can be associated with the oxi-reduction of anyone of the following species: hydroquinone, benzoquinone, resorcinol or catechol. The electrolysis experiments were carried out at 2.4 and 2.5 V on the BDD electrode surface in a solution containing 1x10(-2) M of benzene (below the saturation concentration in aqueous solution), for 3 and 5 h, respectively. The main products measured were: hydroquinone, resorcinol, p-benzoquinone, catechol and phenol. The complete electrochemical benzene degradation was performed in the electrolysis experiments using a rotating BDD disc electrode (2.5 V for 5 h) and the main products detected were all measured at concentrations lower than 10(-5) M in this condition. The boron-doped diamond electrode had proved to be a valuable tool for the electrochemical degradation of the benzene, a very stable chemical compound.
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Affiliation(s)
- Robson T S Oliveira
- GMEME-Instituto de Química de São Carlos, Universidade de São Paulo, Caixa Postal 780, 13566-590 São Carlos, SP, Brazil
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Ju MJ, Yang DH, Takahara N, Hayashi K, Toko K, Lee SW, Kunitake T. Landmine detection: Improved binding of 2,4-dinitrotoluene in a γ-CD/metal oxide matrix and its sensitive detection via a cyclic surface polarization impedance (cSPI) method. Chem Commun (Camb) 2007:2630-2. [PMID: 17579761 DOI: 10.1039/b703132g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly sensitive and selective detection of 2,4-DNT, a representative explosive, was achieved by the synergic effect of molecular imprinting and host (cyclodextrin)-guest interaction in ultrathin layers of TiO(2) and SiO(2) gel; the detection limit using cSPI measurements reached nM concentration.
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Affiliation(s)
- Myung-Jong Ju
- Graduate School of Information Science and Electrical Engineering, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581, Japan
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Yang DH, Ju MJ, Maeda A, Hayashi K, Toko K, Lee SW, Kunitake T. Design of highly efficient receptor sites by combination of cyclodextrin units and molecular cavity in TiO2 ultrathin layer. Biosens Bioelectron 2006; 22:388-92. [PMID: 16935485 DOI: 10.1016/j.bios.2006.06.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Revised: 05/15/2006] [Accepted: 06/04/2006] [Indexed: 11/29/2022]
Abstract
A highly effective approach was developed for sensitive detection of organic substances in water. In order to achieve high sensitivity and selective detection for aromatic compounds, cyclodextrin (CD) hosts and imprinting effects were combined to fabricate binding sites within TiO(2) ultrathin layer. The electrode surface was modified with ultrathin TiO(2) gel film containing a 2:1 complex of beta-CD and bisphenol A (BPA), and then the BPA moiety was removed by washing. The resulting BPA-imprinted TiO(2)/beta-CD film showed specific and sensitive detection of BPA, as confirmed by quartz crystal microbalance (QCM) and cyclic surface-polarization impedance (cSPI) measurements. The high selectivity for BPA relative to structurally related guest molecules was estimated to be 1.6-3.4 at the guest concentration of 2x10(-7)M, and was considered to arise from the synergic effect of the binding site.
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Affiliation(s)
- Do-Hyeon Yang
- Graduate School of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Kitakyushu 808-0135, Japan
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Liu GK, Ren B, Wu DY, Duan S, Li JF, Yao JL, Gu RA, Tian ZQ. Effect of Intrinsic Properties of Metals on the Adsorption Behavior of Molecules: Benzene Adsorption on Pt Group Metals. J Phys Chem B 2006; 110:17498-506. [PMID: 16942090 DOI: 10.1021/jp060485z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Investigation of benzene adsorption on different metal surfaces closer to a practical system appears to be a very important intermediate stage to utilize the conclusion obtained on single-crystal surfaces. In this paper, we studied the electrochemical adsorption behaviors of benzene on roughened Pt group electrodes using surface enhanced Raman spectroscopy (SERS). The effects of potential, surface roughness, and benzene concentration were investigated. Significant difference in surface Raman spectra of benzene on Ru, Rh, Pd, and Pt surfaces were found. On Pt surfaces, the parallel-chemisorbed benzene, the vertical dissociated chemisorbed benzene, and the physisorbed benzene were observed, evidenced by the ring vibration mode appearing at 872, 1012, and 991 cm(-1), respectively. On Pd, only parallel-chemisorbed benzene and physisorbed benzene were found. On Rh and Ru, the SERS signals were mainly from the parallel-chemisorbed benzene, with an extremely weak signal from the physisorbed benzene. The potential dependent study reveals that the parallel-chemisorbed species interacts strongest with the substrate, while the physisorbed species can be easily removed at positive potentials. The models for the adsorbed benzene were given to account for the different types of benzene on these Pt group metals. The difference in the atomization heat of the four metals was used to interpret the different interaction strength of benzene with Pt group metals.
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Affiliation(s)
- Guo-Kun Liu
- Department of Chemistry, Xiamen University, 361005 Xiamen, China
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Kariya N, Fukuoka A, Ichikawa M. Direct PEM fuel cell using “organic chemical hydrides” with zero-CO2 emission and low-crossover. Phys Chem Chem Phys 2006; 8:1724-30. [PMID: 16633657 DOI: 10.1039/b518369c] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of "organic chemical hydrides" such as cyclohexane, methylcyclohexane, cyclohexene, 2-propanol, and cyclohexanol were applied to the direct PEM fuel cell. High performances of the PEM fuel cell were achieved by using cyclohexane (OCV = 920 mV, PD(max) = 15 mW cm(-2)) and 2-propanol (OCV = 790 mV, PD(max) = 78 mW cm(-2)) as fuels without CO(2) emissions. The rates of fuel crossover for cyclohexane, 2-propanol, and methanol were estimated, and the rates of fuel permeation of cyclohexane and 2-propanol were lower than that of methanol. Water electrolysis and electro-reductive hydrogenation of acetone mediated by PEM were carried out and formation of 2-propanol in cathode side was observed. This system is the first example of a "rechargeable" direct fuel cell.
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Affiliation(s)
- Nobuko Kariya
- Catalyst Research Centre, Hokkaido University, N21 W10 Sapporo, Hokkaido, 001-0021, Japan
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Influence of benzene on the HUPD and anion adsorption on Pt(110), Pt(100) and Pt(111) electrodes in aqueous H2SO4. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2004.12.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Jerkiewicz G, DeBlois M, Radovic-Hrapovic Z, Tessier JP, Perreault F, Lessard J. Underpotential deposition of hydrogen on benzene-modified Pt(111) in aqueous H2SO4. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:3511-3520. [PMID: 15807596 DOI: 10.1021/la048290a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Pt(111) electrode is modified by an overlayer of C6H6 (ads) upon its cycling in the 0.05-0.80 V range in aq H2SO4 + 1 mM C6H6. The C6H6 (ads) overlayer significantly changes the underpotential-deposited H (H(UPD)) and anion adsorption, and cyclic-voltammetry (CV) profiles show a sharp cathodic peak and an asymmetric anodic one in the 0.05-0.80 V potential range. The C6H6 (ads) layer blocks the (bi)sulfate adsorption but facilitates the adsorption of one monolayer of H(UPD). Cycling of the benzene-modified Pt(111) in benzene-free aq 0.05 H2SO4 from 0.05 to 0.80 V results in a partial desorption of C6H6 (ads) and in a partial recovery of the CV profile characteristic of an unmodified Pt(111). The peak potential of the cathodic and anodic feature is independent of the scan rate, s (10 < or = s < or = 100 mV s(-1)), and the peak current density increases linearly with an increase of the scan rate. Temperature variation modifies the peak potential and current density but does not affect the charge density of the cathodic or anodic feature. Temperature-dependent studies allow us to determine the thermodynamic state function for the H(UPD) adsorption and desorption. Delta G degrees(ads)(H(UPD))assumes values from -4 to -12 kJ mol(-1), while has values from 9 to 14 kJ mol(-1). The values of delta Delta G degrees (delta Delta G degrees = delat Delta G degrees(ads) + delta Delta D degrees(des)) decrease almost linearly from 6 kJ mol(-1) at theta(H(UPD) --> 0 to 0 kJ mol(-1) at theta(H(UPD) --> 1. The nonzero values of delta Delta G degrees testify that the adsorbing and desorbing H(UPD) adatoms interact with an energetically different substrate. The lateral interactions changed from repulsive (omega = 29 kJ mol(-1) at theta(H(UPD) --> 0) to attractive (omega = -28 kJ mol(-1) at theta(H(UPD) --> 1) as the H(UPD) coverage increases. The values of delta S degrees(ads)(H(UPD)) increase from 19 to 56 J K(-1) mol(-1), while those of delta S degrees(des)(H(UPD)) decrease from 45 to -30 J K(-1) mol(-1) with an increase of H(UPD) coverage. The values of delta H degrees(des)(H(UPD)) and delta H degrees(des)(H(UPD)) vary from 0 to 27 kJ mol(-1). The Pt(111)-H(UPD) surface bond energy at the benzene-modified Pt(111) electrode falls in the 191-218 kJ mol(-1) range and is weaker than in the case of the unmodified Pt(111) electrode in the same electrolyte.
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Affiliation(s)
- Gregory Jerkiewicz
- Department of Chemistry, Queen's University, Kingston, Ontario, K7L 3N6 Canada.
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Liu GK, Ren B, Gu RA, Tian ZQ. The electrochemical halogenation of benzene: an in situ confocal microprobe Raman study. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)01296-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Montilla F, Morallón E, Vázquez J. Electrochemical study of benzene on Pt of various surface structures in alkaline and acidic solutions. Electrochim Acta 2002. [DOI: 10.1016/s0013-4686(02)00520-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Liu GK, Yao JL, Ren B, Gu RA, Tian ZQ. Confocal microprobe Raman spectroscopic study of the electrochemical reduction of benzene on platinum and rhodium electrodes. Electrochem commun 2002. [DOI: 10.1016/s1388-2481(02)00318-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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