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Haakansson CT, Corkish TR, Watson PD, McKinley AJ, Wild DA. The bromide-bromomethyl radical dimer complex: Anion photoelectron spectroscopy and CCSD(T) calculations. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.138060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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2
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Zhai S, Zhang W, Li T, Zhang W, Lv L, Pan B. Sodium hypochlorite assisted membrane cleaning: Alterations in the characteristics of organic foulants and membrane permeability. CHEMOSPHERE 2018; 211:139-148. [PMID: 30071425 DOI: 10.1016/j.chemosphere.2018.07.144] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/20/2018] [Accepted: 07/23/2018] [Indexed: 06/08/2023]
Abstract
Chemical cleaning is an important approach for alleviating severe fouling in membrane separation processes. In this study, lysozyme (LYS) was exposed to sodium hypochlorite (NaClO) with varied concentrations (0-2000 ppm) to understand the changes in the physicochemical properties and functional groups as well as the variations in membrane permeabilities. The results showed that membrane filterability exhibited an obvious 'U-shaped' trend, and the valley existed when the ratio of Cl/C (the ratio of NaClO and TOC concentrations in feed water) is among 1.35-3.09. Upon exposure to low dose NaClO, three-dimensional fluorescence excitation-emission matrix (3D-EEM) spectra showed that tryptophan protein substances were transformed to more hydrophobic humic-like substances. Fourier transform infrared (FTIR) analysis further confirmed that exposure to low dose NaClO promoted the breakage of aromatic substituents, leading to the formation of hydrophobic condensed aromatic substances. On the contrary, at high NaClO loads, protein structures were destroyed completely and almost no obvious fluorescent intensities could be detected, which promoted the recovery of membrane filterabilities. Notably, the chemical cleaning mechanisms of fouled membranes with NaClO were understood in depth in this study. These results provide new information about the oxidation products of LYS and the cleaning efficiency upon exposure to NaClO.
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Affiliation(s)
- Shu Zhai
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023, PR China
| | - Weiming Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023, PR China; State Environmental Protection Engineering Center for Organic Chemical Wastewater Treatment and Resource Reuse, Nanjing University, 210023, PR China.
| | - Ting Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023, PR China
| | - Wenbin Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023, PR China
| | - Lu Lv
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023, PR China
| | - Bingcai Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023, PR China
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Le Vot C, Lemaire J, Pernot P, Heninger M, Mestdagh H, Louarn E. Oxygen anion (O - ) and hydroxide anion (HO - ) reactivity with a series of old and new refrigerants. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:336-352. [PMID: 29271073 DOI: 10.1002/jms.4054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/08/2017] [Accepted: 12/12/2017] [Indexed: 06/07/2023]
Abstract
The reactivity of a series of commonly used halogenated compounds (trihalomethanes, chlorofluorocarbon, hydrochlorofluorocarbon, fluorocarbons, and hydrofluoroolefin) with hydroxide and oxygen anion is studied in a compact Fourier transform ion cyclotron resonance. O- is formed by dissociative electron attachment to N2 O and HO- by a further ion-molecule reaction with ammonia. Kinetic experiments are performed by increasing duration of introduction of the studied molecule at a constant pressure. Hydroxide anion reactions mainly proceed by proton transfer for all the acidic compounds. However, nucleophilic substitution is observed for chlorinated and brominated compounds. For fluorinated compounds, a specific elimination of a neutral fluorinated alkene is observed in our results in parallel with the proton transfer reaction. Oxygen anion reacts rapidly and extensively with all compounds. Main reaction channels result from nucleophilic substitution, proton transfer, and formal H2+ transfer. We highlight the importance of transfer processes (atom or ion) in the intermediate ion-neutral complex, explaining part of the observed reactivity and formed ions. In this paper, we present the first reactivity study of anions with HFO 1234yf. Finally, the potential of O- and HO- as chemical ionization reagents for trace analysis is discussed.
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Affiliation(s)
- Clotilde Le Vot
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Joël Lemaire
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Pascal Pernot
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Michel Heninger
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
- AlyXan, Juvisy-sur-Orge, France
| | - Hélène Mestdagh
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
| | - Essyllt Louarn
- Laboratoire de Chimie Physique, CNRS, Université Paris Sud, F-91405, Orsay, France
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Vogelhuber KM, Wren SW, McCoy AB, Ervin KM, Lineberger WC. Photoelectron spectra of dihalomethyl anions: Testing the limits of normal mode analysis. J Chem Phys 2011; 134:184306. [DOI: 10.1063/1.3585606] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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Ghosh A, Jose DA, Das A, Ganguly B. A density functional study towards substituent effects on anion sensing with urea receptors. J Mol Model 2010; 16:1441-8. [DOI: 10.1007/s00894-010-0663-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Accepted: 12/21/2009] [Indexed: 10/19/2022]
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Bailleux S, Kania P, Skřínský J, Okabayashi T, Tanimoto M, Matsumoto S, Ozeki H. Hyperfine Resolved Fourier Transform Microwave and Millimeter-Wave Spectroscopy of the Iodomethyl Radical, CH2I (X̃2B1). J Phys Chem A 2010; 114:4776-84. [DOI: 10.1021/jp909323h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | - Hiroyuki Ozeki
- Department of Environmental Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi 274-8510, Japan
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Rosen BM, Percec V. Implications of monomer and initiator structure on the dissociative electron‐transfer step of SET‐LRP. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/pola.22888] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Ozeki H, Okabayashi T, Tanimoto M, Saito S, Bailleux S. Hyperfine resolved spectrum of the bromomethyl radical, CH2Br, by Fourier transform microwave spectroscopy. J Chem Phys 2007; 127:224301. [DOI: 10.1063/1.2805187] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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9
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Xavier ES, Rocha WR, Da Silva JC, Dos Santos HF, De Almeida WB. Ab initio thermodynamic study of the reaction of CF2Cl2 and CHF2Cl CFCs species with OH radical. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.09.086] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Larkin JD, Bock CW, Schaefer Iii HF. Assessing Alkyl-, Silyl-, and Halo-Substituent Effects on the Electron Affinities of Silyl Radicals. J Phys Chem A 2005; 109:10100-5. [PMID: 16838930 DOI: 10.1021/jp052439p] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Neutral anion energy differences for a large class of alpha-substituted silyl radicals have been computed to determine the effect of alkyl, silyl, and halo substituents on their electron affinities. In particular, we report theoretical predictions of the adiabatic electron affinities (AEAs), vertical electron affinities (VEAs), and vertical detachment energies (VDEs) for a series of methyl-, silyl-, and halo-substituted silyl radical compounds. This work utilizes the carefully calibrated DZP++ basis set, in conjunction with the pure BLYP and OLYP functionals, as well as with the hybrid B3LYP, BHLYP, PBE1PBE, MPW1K, and O3LYP functionals. Bromine has the largest effect in stabilizing the anions, and the BLYP/DZP++ AEA for SiBr(3) is 3.29 eV. The other predicted electron affinities are for SiH(3) (1.37 eV), SiH(2)CH(3) (1.09 eV), SiH(2)F (1.54 eV), SiH(2)Cl (1.94 eV), SiH(2)Br (2.05 eV), SiH(2)(SiH(3)) (1.77 eV), SiH(CH(3))(2) (0.92 eV), SiHF(2) (1.86 eV), SiHCl(2) (2.53 eV), SiHBr(2) (2.67 eV), Si(CH(3))(3) (0.86 eV), SiF(3) (2.66 eV), SiCl(3) (3.21 eV), Si(SiH(3))(3) (2.25 eV), and SiFClBr (3.13 eV). For the five silyl radicals where experimental data are available, the BLYP functional gives the most accurate determination of AEAs; the average absolute error is 0.04(1) eV, whereas the corresponding errors for the O3LYP, MPW1K, PBE1PBE, B3LYP, OLYP, and BHLYP functionals are 0.05(8), 0.06(0), 0.06(3), 0.08(5), 0.11(5), and 0.15(3) eV, respectively.
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Affiliation(s)
- Joseph D Larkin
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602, USA
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Larkin JD, Schaefer HF. The ability of silylenes to bind excess electrons: electron affinities of SiX(2), and SiXY species (X,Y=H,CH(3),SiH(3),F,Cl,Br). J Chem Phys 2004; 121:9361-7. [PMID: 15538855 DOI: 10.1063/1.1790951] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recently, Ishida and co-workers have isolated silylene radical anions via the one-electron reduction of isolable cyclic dialkylsilylenes, discovering these corresponding radical anions to be relatively stable at low temperatures. Herein we report theoretical predictions of the adiabatic electron affinities (AEA), vertical electron affinities, and vertical detachment energies of a series of methyl, silyl, and halosubstituted silylene compounds. This research utilizes the carefully calibrated DZP++ basis with the combination of the popular nonhybrid and hybrid DFT functionals, BLYP, B3LYP, and BHHLYP. The level of theory employed and the ensemble of species under study confirm the ability of silylenes to bind excess electrons with Si(SiH(3))(2) being the most effective, having a predicted AEA of 1.95 eV. While it is known that methyl substituents have a diminishing effect on the computed electron affinities (EAs), it is shown that fluorine shows an analogous negative effect. Similarly, previous suggestions that Si(CH(3))(2) will not bind an electron appear incorrect, with EA[Si(CH(3))(2)] predicted here to be 0.46 eV.
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Affiliation(s)
- Joseph D Larkin
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602, USA
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Simmonett AC, Wheeler SE, Henry F. Schaefer III*. The Vinyl Radical and Fluorinated Vinyl Radicals, C2H3-nFn (n = 0−3), and Corresponding Anions: Comparison with the Isoelectronic Complexes [X···YC≡CZ]-. J Phys Chem A 2004. [DOI: 10.1021/jp031240e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Andrew C. Simmonett
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602
| | - Steven E. Wheeler
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602
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