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reagent types and action mechanisms in ilmenite flotation:A review

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International Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1656-1669页

作者： Jiaozhong Cai Jiushuai Deng Liang Wang Mingzhen Hu Hongxiang Xu Xiaoan Hou Bozeng Wu Shimei Li School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing 100083China ZHONGGUANCUN Green Mine Industry Alliance Beijing 100083China Liuzhou China-Tin Nonferrous Design and Research Institute Co. Ltd.CHINA TIN GROUPLiuzhou 545006China State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China

Ilmenite is an essential mineral for the extraction of *** physical separation methods have difficulty recovering fine ilmenite,and dressing plants have begun applying flotation to recover *** interaction of reagent groups with Ti and Fe sites on the ilmenite surface dramatically influences the ilmenite ***,the investigation on Fe sites has received more attention because the activity of Ti is lower than that of *** the activators on ilmenite flotation,most are metal ions but typically lead *** metal ions of activators promote ilmenite flotation by increasing the active sites on the ilmenite *** reagents have a better selective separation of ilmenite than single reagents due to their synergistic *** the lead ion(Pb^(2+))and the benzyl hydroxamic acid(BHA)into a Pb-BHA complex has a marked effect on ilmenite flotation,which puts forward a new idea of developing combined reagents for ilmenite *** review considers reagent types and action mechanisms in ilmenite *** the basis of the analysis of previous research,a brief future outlook of reagent types and action mechanisms in ilmenite flotation is also proposed in this study.

关键词： ilmenite flotation reagent action mechanism combined reagents

Chromo-chemodosimetric detection for Fe^(2+) by Fenton reagent-induced chromophore-decolorizing of halogenated phenolsulfonphthalein derivatives

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Science China Chemistry 2010年第6期53卷 1398-1405页

作者： ZHENG Kuan,LAI ChengYue,HE LiPing & LI Fang Key Laboratory of Green Chemistry and Technology,Ministry of Education College of Chemistry,Sichuan University,Chengdu 610064,China Key Laboratory of Green Chemistry and Technology Ministry of Education College of Chemistry Sichuan University Chengdu China

A commercially-available sulfonphthalein derivative was demonstrated to be a chemodosimeter for Fe2+ and its sensing behavior was further investigated by UV-vis spectroscopy in aqueous media under the optimum *** the presence of chlorophenol red (CPR) and H2O2,the absorption maximum at 435 nm decreased upon addition of Fe2+,resulting in a significant color change of the CPR solution from yellow to *** chemosensor system did not show significant responses to a series of other metal ions including Al3+,Zn2+,Cd2+,Hg2+,Mn2+,Co2+,Fe3+,Ni2+,Cu2+,La3+,Ce4+,Th4+,Pd2+,Pb2+,Sb3+,Cr3+,Au3+,Ag+,Nd3+,Sm3+,alkali and alkaline earth metal cations,allowing for highly selective naked-eye detection of Fe2+.Quantitative analysis was carried out kinetically for practicable the Fe2+ assay when either fixed time method or the initial rate method was *** the detecting time was set,the decrease of absorbance signal was linear with Fe2+ concentration in the range of 0 to 7.50 × 10-5 mol L-1 and the regression equation was ΔA = 0.00759 + 0.00593CFe with a correlation coefficient r = *** chemodosimetric system has employed an irreversible Fenton reagent-promoted oxidation of the CPR free chromophore and the hydroxyl radicals were generated in the presence of both Fe2+ and hydrogen *** mechanistic interpretation of the signaling process was partially confirmed by the radical scavenging experiment and the FT-IR analysis of the intermediates formed at different reaction periods.

关键词： colorimetric chemosensor ferrous ion sulfonphthalein Fenton reagent

Double dehydrogenation of carbocyclic β-dicarbonyl compounds:Koser's reagent can do what iodine(V) reagents can

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Science China Chemistry 2019年第5期62卷 597-601页

作者： Shan-Shan Liu Li Wang Ya-Nan Duan Ao Yu Chi Zhang State Key Laboratory of Elemento-Organic Chemistry Collaborative Innovation Center of Chemical Science and Engineering (Tianjin)College of ChemistryNankai University Department of Chemical Engineering and Safety Binzhou University Central Laboratory College of ChemistryNankai University

Koser's reagent is found to be effective in the oxidative double dehydrogenation of various carbocyclic β-dicarbonyl compounds,which constitutes the first example on dehydrogenation reactivity of hypervalent iodine(Ⅲ) reagents for carbocyclic carbonyl compounds. DFT calculations reveal that the rate-determining step is the electrophilic addition of PhI+OH onto enolate of monodehydrogenated product.

关键词： Koser’s reagent double dehydrogenation hypervalent twisting 2,3-benzotropone DFT calculations

A bench-stable reagent for C-4 selective deuteriodifluoromethylation of azines

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Chinese Chemical Letters 2022年第11期33卷 4817-4821页

作者： Junqing Liang Lefeng Dong Feng Qian Yijin Kong Mingxia Wang Xiaoyong Xu Xusheng Shao Zhong Li Shanghai Key Laboratory of Chemical Biology School of PharmacyEast China University of Science and TechnologyShanghai 200237China Research Center of Analysis and Test School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Deuteriodifluoromethyl(CF_(2)D)is a challenging and important functional group due to difficult deuterium incorporation and lack of effective precursor ***,we report a bench-stable reagent,deuteriodifluoromethyl phosphine(DDFP)from cheap deuterium source for selectivity deuteriodifluoromethylation of azines with a high deuterium incorporation *** late-stage modification of complex molecules further confirmed the potential of this reagent for practical *** expect that our reagent to find applications in synthesis of isotope-labelled molecules of interests for drug-discovery and related ilucidation of mechanism of action.

关键词： reagent Deuterium Difluoromethylation C-4 selective Azines

Allyltin tribromide: A versatile reagent involved in the ring-opening of epoxides

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Science China Chemistry 2010年第6期53卷 1294-1301页

作者： CHEN GuoHong,WANG Xin,JIN XiaoQian,LIU LingYan,CHANG WeiXing & LI Jing State Key Laboratory and Research Institute of Elemento-organic Chemistry,Nankai University,Tianjin 300071,China State Key Laboratory and Research Institute of Elemento-organic Chemistry Nankai University Tianjin China

This paper presents a versatile reagent for epoxide *** allyltin tribromide could act as a novel and easily prepared allylation reagent and halide atom donor to convert epoxides to the corresponding homoallyl alcohols and halohydrins in high yields with excellent regioselectivities under mild reaction conditions,*** could also act as a Lewis acid to catalyze the ring opening reactions of epoxides with alcohols.

关键词： versatile reagent allyltin tribromide ring opening of epoxides room temperature

Mechanism of the interaction of color reagent 1, 3-N, N'-bis-4-(4'-nitro benzenediazo) phenyl squaraine with oxoacid anions

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Science China Chemistry 1999年第1期42卷 70-76页

作者：杨明理孙泽民鄢国森 1. Department of Chemistry Sichuan Union University 610064 Chengdu China

By AM1 method, the interactions between 1, 3-N, N’ -Bis-4-(4’ -nitro benzenediazo) phenyl squaraine (BNBPS) and several oxoacid anions have been studied on the basis of the proposed model. The mechanism of the color reactions is suggested and the answers to the question of whether or not BNBPS colorates with HCO 3 - , CO 3 2- , NO2, NO3 etc. are given. It is theoritically predicted that BNBPS might be used as the color reagent for SO 4 2 .

关键词： anion color reagent squaraine derivatives AM1 method.

Branched hybridization chain reaction-using highly dimensional DNA nanostructures for label-free,reagent-less,multiplexed molecular diagnostics

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Microsystems & Nanoengineering 2019年第1期5卷 316-322页

作者： Gaolian Xu Mingliang Lai Rab Wilson Andrew Glidle Julien Reboud Jonathan M.Cooper Division of Biomedical Engineering James Watt School of EngineeringUniversity of GlasgowOakfield AvenueGlasgow G128LTUK

The specific and multiplexed detection of DNA underpins many analytical methods,including the detection of microorganisms that are important in the medical,veterinary,and environmental *** achieve such measurements generally requires enzyme-mediated amplification of the low concentrations of the target nucleic acid sequences present,together with the precise control of temperature,as well as the use of enzyme-compatible *** inevitably leads to compromises between analytical performance and the complexity of the *** hybridization chain reaction(HCR)provides an attractive alternative,as a route to enzyme-free DNA *** date,the linear nucleic acid products,produced during amplification,have not enabled the development of efficient multiplexing strategies,nor the use of label-free ***,we show that by designing new DNA nanoconstructs,we are able,for the first time,to increase the molecular dimensionality of HCR products,creating highly branched amplification products,which can be readily detected on label-free *** show that this new,branching HCR system offers a route for enzyme-free,label-free DNA detection,we demonstrate the multiplexed detection of a target sequence(as the initiator)in whole *** the future,this technology will enable rapid point-of-care multiplexed clinical analysis or in-the-field environmental monitoring.

关键词： reagent attractive branching

Chen's reagent: A Versatile reagent for Trifluoromethylation,Difluoromethylenation, and Difluoroalkylation in Organic Synthesis

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Chinese Journal of Chemistry 2020年第2期38卷 202-212页

作者： Qiqiang Xie Jinbo Hu Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Ling-Ling RoadShanghai 200032China

Methyl fluorosulfonyldifluoroacetate(FSO2CF2CO2Me or MFSDA),often called"Chen's reagent",is commonly used to synthesize trifluoromethylated and difluoroalkylated *** important reagent was initially developed as an efficient trifluoromethylating agent by Professor Qing-Yun Chen and co-workers at Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences in 1989.

关键词： compounds. reagent reagent

Polyvinylpolypyrrolidone-bromine complex:Mild and efficient polymeric reagent for bromination of activated aromatic compounds

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Chinese Chemical Letters 2011年第1期22卷 13-17页

作者： Masoud Mokhtary Moslem M.Lakouraj Department of Chemistry Islamic Azad University-Ayatollah Amoli BranchP.O.Box 678AmolIran Department of Organic-Polymer Chemistry Mazandaran UniversityBabolsar 47416Iran

Mild and efficient method for bromination of electron-rich aromatic compounds is described using polyvinylpolypyrrolidone- bromine complex （PVPP-Br2）. The reaction proceeded smoothly with phenols and N.N-alkylated a... 详细信息

关键词： Polyvinylpolypyrrolidone Phenols Bromination reagent