- General Strategy to Fabricate Metal-Incorporated Pyrolysis-Free Covalent Organic Framework for Efficient Oxygen Evolution Reaction
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Because of the permission of the manipulations of modular construction on the atomic level, covalent organic frameworks (COFs) have attracted extensive attention in the electrocatalytic field. Owing to the lack of metal sites in pristine COFs constructed only by metal-free organic building units, it generally exhibits extremely low electrocatalytic activity. Thereby, linking metal sites on the backbone of pyrolysis-free COFs but not loading them on the surface to enhance the electrocatalytic activity is highly desirable but still remains a huge challenge. To this end, herein, we report an efficient and general cation-exchange strategy to synthesize Ni/Fe metal-ion-incorporated COFs (NixFe1-x?COF-SO3) for the oxygen evolution reaction (OER) based on the fundamental structure design of COFs. Impressively, the turnover frequency (TOF) value in Ni0.5Fe0.5?COF-SO3 reaches 0.14 s-1 at the overpotential of 300 mV, which outperforms most recently reported OER electrocatalysts, indicative of ultrahigh metal-atom utilization efficiency.
- Gao, Zhi,Gong, Le Le,He, Xiang Qing,Luo, Feng,Su, Xue Min,Xiao, Long Hui
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- Flexible and robust bimetallic covalent organic frameworks for the reversible switching of electrocatalytic oxygen evolution activity
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Flexible and robust catalysts present a highly intriguing issue owing to their unique dynamic and reversible switching nature, which can provide a solution to maximize the atom utilization efficiency. Herein, a convenient and efficient cation-exchange strategy was developed to prepare flexible and robust Co/V-incorporated bimetallic COF electrocatalysts (namely, CoxV1-x?COF-SO3) for the oxygen evolution reaction (OER). As expected, in a 1.0 M KOH electrolyte, the optimized bimetallic Co0.5V0.5?COF-SO3 showed high turnover frequency (TOF) (0.098 s-1) at the overpotential of 300 mV, which was superior to that of most of the recently reported excellent Co-based OER electrocatalysts, exhibiting high atom utilization efficiency. Most importantly, the flexible nature of Co0.5V0.5?COF-SO3 was also observed. After treatment with hydrochloric acid, the reformation of the catalysis-inert phase of COF-SO3H was observed. This unique transformation from the catalysis-active phase of Co0.5V0.5?COF-SO3 to the catalysis-inert phase of COF-SO3H can be repeated, suggesting reversible switching of OER activity, which are almost impossible to achieve in conventional catalysts. This work provides a new concept for the fundamental design of catalysts with reversible switching properties to improve the atom utilization efficiency and simplify the procedures of catalyst regeneration.
- Gao, Zhi,He, Xiangqing,Huang, Xinhui,Huang, Yuxing,Luo, Feng,Su, Xuemin,Xiao, Longhui,Yu, Yi,Yu, Zhiwu
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p. 5907 - 5912
(2020/04/08)
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- Ultralow-content palladium dispersed in covalent organic framework for highly efficient and selective semihydrogenation of alkynes
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Developing noble-metal-based catalysts with ultralow loading to achieve excellent performance for selective hydrogenation of alkynes under mild reaction conditions is highly desirable but still faces huge challenges. To this end, a SO3H-anchored covalent organic framework (COF-SO3H) as the support was deliberately designed, and then ultralow-content Pd (0.38 wt %) was loaded by a wet-chemistry immersion dispersion method. The resulting Pd0.38/COF-SO3H composite exhibits outstanding performance for the selective hydrogenation of phenylacetylene with 97.06% conversion and 93.15% selectivity to styrene under mild reaction conditions (1 bar of H2, 25 °C). Noticeably, the turnover frequency value reaches as high as 3888 h-1, which outperforms most of reported catalysts for such use. Moreover, such a catalyst also exhibits excellent activity for a series of other alkynes and high stability without obvious loss of catalytic performance after five consecutive cycles.
- Li, Jian Hong,Yu, Zhi Wu,Gao, Zhi,Li, Jian Qiang,Tao, Yuan,Xiao, Yu Xin,Yin, Wen Hui,Fan, Ya Ling,Jiang, Chao,Sun, Li Jun,Luo, Feng
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supporting information
p. 10829 - 10836
(2019/08/22)
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- CuFe2O4@PDA magnetic nanomaterials with a core-shell structure: Synthesis and catalytic application in the degradation of methylene blue in water
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In this paper, core-shell polydopamine (PDA)-encapsulated CuFe2O4 (CuFe2O4@PDA) magnetic nanoparticles (MNPs) were synthesized through in situ self-polymerization for the first time. The size of the core-shell product can be controlled by tuning the dopamine monomer concentration. The formation of a PDA layer effectively enhanced the catalytic performance and provided a large specific surface area which offered more active sites for the effective interaction. The as-synthesized CuFe2O4@PDA MNPs were characterized and their catalytic activity was evaluated using the degradation of methylene blue (MB) in the presence of H2O2 as a model reaction. The experimental results showed that MB could be degraded efficiently using CuFe2O4@PDA MNPs as a catalyst. Under the optimized conditions, the degradation efficiency of MB was above 97%. Furthermore, a possible reaction mechanism was discussed. Finally, the catalyst was used for effective degradation of MB in a Yellow River water sample, which indicates its potential for practical applications in water pollutant removal and environmental remediation.
- Ma, Su-Dai,Feng, Jie,Qin, Wen-Jie,Ju, Yu-Yun,Chen, Xing-Guo
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p. 53514 - 53523
(2015/06/30)
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- Development of an efficient ruthenium catalyzed synthetic process and mechanism for the facile conversion of benzothiazoles to orthanilic acids
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Ruthenium-Schiff base complex catalyzed efficient protocol has been developed for the synthesis of orthanilic acids from benzothiazoles in good to excellent yields using N-haloamines. Hexa-coordinated ruthenium complex with Schiff base and triphenylphosphine ligands has been prepared and its catalytic function was invented for the synthesis of orthanilic acids. The synthetic process utilizes our efficient method for the selective and preferential oxidation of thiazole ring of benzothiazoles using N-haloamines without effecting phenyl ring. The detailed catalytic, mechanistic and kinetic investigations have been made for the synthetic reactions. Solvent isotope studies have been made in H2O-D2O and the reactions were carried out at different temperatures. Under the identical set of conditions, the kinetics of catalyzed reactions has been compared with uncatalyzed reactions and found that the catalyzed reactions are 9-11 folds faster. The catalytic constants (KC) have been calculated for each N-haloamine at different temperatures and the values of activation parameters with respect to the catalyst have been evaluated. Spectroscopic evidence for the formation of 1:1 complex between N-haloamine and ruthenium has been obtained. The observed results have been explained by a plausible mechanism and the related rate law has been deduced.
- Jagadeesh,Karthikeyan,Nithya,Sandhya, Y. Sree,Reddy, S. Sudhaker,Reddy, P. Pradeep Kumar,Kumar, M. Vinod,Charan, K.T. Prabhu,Narender,Bhagat
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experimental part
p. 99 - 107
(2010/12/18)
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- Azo dyes
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Compound of the formula (I) whereinR is hydrogen or optionally substituted C1-C6-alkyl,R1 is hydrogen or C1-C6-alkyl,R2 is hydrogen, optionally substituted C1-C6-alkyl or optionally substituted phenyl,the ring D is optionally substituted by one or more identical or different substituents selected from the group consisting of C1-C6-alkyl, C1-C6-alkoxy, halogen, especially F, Cl and Br, and SO3H,m is 0 or 1,n is 1, 2 or 3 and as a function of nX is a mono-, di- or trivalent acyl radical, pyrimidine or 1,3,5-triazine radical which is not fiber-reactive.
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- Process for dyeing keratinous fibers with aminoindoles and oxidation dye precursors at basic Ph's and dyeing agents
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The invention relates to a process for dyeing keratinous fibres, which consists in applying to these fibres a composition containing, in a suitable medium for dyeing, at least one coupler of formula: STR1 where R1 denotes hydrogen or alkyl, R2 and R3 denote hydrogen, alkyl, COOR' where R' is alkyl or hydrogen, at least one of the groups R2 and R3 denoting hydrogen, R4 denotes hydrogen, alkyl, hydroxyalkyl, polyhydroxyalkyl or aminoalkyl, Z1 and Z2 denote hydrogen, alkyl, hydroxyl, halogen, alkoxy, at least one of the groups Z1 and Z2 is other than hydrogen at least one oxidation dye precursor, at least one oxidizing agent, the pH of the composition applied to the fibres being higher than 7.
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- Methods for dyeing keratinous fibers with compositions which contain aminoindole couplers, oxidation dye precursors, and oxidizing agents at acid pHs
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A method for dyeing keratin fibers, wherein a composition is applied to said fibers which contains, in a suitable dyeing medium, at least one coupler having formula (I) STR1 wherein R1 is hydrogen or alkyl; R2 and R3 are hydrogen, alkyl, COOR', where R' is alkyl or hydrogen; R4 is hydrogen, hydroxyalkyl, alkyl, polyhydroxyalkyl or acetyl or aminoalkyl wherein the amine may be mono- or disubstituted by alkyl; Z1 and Z2 are hydrogen, alkyl, hydroxy, halogen, alkoxy or a salt thereof; at least one precursor of an oxidation hair dye; and at least one oxidizing agent, the pH of the composition applied to the fibers being less than 7.
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- 3-substituted para-aminophenols
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The invention concerns the use of a 3-substituted para-aminophenol as an oxidation dye precursor for dyeing keratinous fibres, in particular human hair. The 3-substituted para-aminophenol has formula: STR1 where R1 represents alkyl, alkenyl, mono- or polyhydroxyalkyl, nitrile, cyanoalkyl, halogenoalkyl, aminoalkyl or alkoxyalkyl and R2 represents hydrogen, alkyl or mono- or polyhydroxyalkyl, provided that when R2 is hydrogen R1 is not methyl or trifluoromethyl, and to addition salts thereof with an acid. The invention also concerns dye compositions containing compound (I). The invention further concerns novel 3-substituted para-aminophenols.
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- Triazinyl reactive dyestuffs in which triazinyl group is further substituted with a beta-chloroethylsulfonyl- or vinylsulfonylbutyrylamino moiety
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Reactive dyes of the formula STR1 in which D is the radical of an organic dye of the monoazo, polyazo, metal complex azo, anthraquinone, phthalocyanine, formazan, azomethine, dioxazine, phenazine, stilbene, triphenylmethane, xanthene, thioxanthrone, nitroaryl, naphthoquinone, pyrenequinone or perylenetetracarbimide series, R is hydrogen or substituted or unsubstituted C1-4 -alkyl, X is a substituent which is detachable as an anion, B is a radical of the formula STR2 R1 and R2, independently of each other, are hydrogen or substituted or unsubstituted C1-4 -alkyl or phenyl, A is a substituted or unsubstituted aliphatic or aromatic bridge member, Y is a --CO--Z or --SO2 --Z radical, Z is an aliphatic, aromatic or heterocyclic reactive radical, and n is 1 or 2, are suitable for dyeing or printing cellulose-containing and nitrogen-containing materials and in high dyeing yield produce dyeings and prints having good fastness properties.
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- Reactive disazo dyestuffs having a fluorocontaining reactive group and a sulphatoethylsulphone substituent
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Dyestuffs of the formula STR1 wherein B=CH=CH2 or CH2 CH2 OSO3 H, u and v=H or SO3 H, with u=v, R=Cl, Br, C1 -C4 -alkyl, C1 -C4 -alkoxy, COOH, SO3 H, NHCOCH3, SO2 CH2 CH2 OSO3 H n=0, 1 or 2 STR2 These dyestuffs are outstandingly suitable for the dyeing and printing of materials containing hydroxyl groups or amide groups, such as cellulose, wool and polyamide, and give dyeings with good wet and light fastness properties.
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- Reactive dyestuffs comprising a triazine moiety and a vinylsulfonyl moiety both being linked by a substituted alkylene bridge member
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A reactive dye of the formula STR1 in which: F is a radical selected from the group consisting of metal-free or metal-containing monoazo or disazo dyes containing at least one --SO3 H group, anthraquinone dyes, sulfophthalocyanine dyes, formazan dyes, phenazine dyes, oxazine dyes and nitroaryl dyes, R is hydrogen, C1 -C4 alkyl which is unsubstituted or substituted with --COOH or --SO3 H, cyanoethyl, or hydroxyethyl, X is fluorine, chlorine, bromine, --SO3 H, phenylsulfonyl or C1 -C4 -alkylsulfonyl, p is 1 or 2 and A is a radical of the formula STR2 in which: Y is chlorine, bromine, fluorine, --OH, --OSO3 H, --O-acyl, --CN, --COOH, --COO--C1 -C4 -alkyl, --CONH2 or --SO2 --Z, the group designated "alk" is a straight or branched polymethylene radical having 2 to 6 carbon atoms, V is STR3 hydrogen or C1 -C4 -alkyl which is unsubstituted or substituted by C1 -C2 -alkoxy, carboxyl, sulfo, halogen or hydroxy, Z is β-halogenoethyl, vinyl or β-acetoxyethyl, or A is a radical of the formulae STR4 in all of which R' is C1-6 -alkyl or hydrogen, Z is as defined above, o is 0 to 6, and m is 2 to 6.
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- Triazinyl reactive dyes containing additional fiber reactive groups bound through the sulfonylalkylaminoalkylamino bridge
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The invention relates to novel useful reactive dyes of the formula I STR1 in which: F is a radical selected from the group consisting of metal-free or metal-containing monoazo or disazo dyes containing at least one --SO3 H group, anthraquinone dyes, sulfophthalocyanine dyes, formazan dyes, phenazine dyes, oxanine dyes and nitroaryl dyes, R is hydrogen, C1 -C4 alkyl which is unsubstituted or substituted with --COOH or --SO3 H, cyanoethyl, or hydroxyethyl, X is fluorine, chlorine, bromine, --SO3 H, phenylsulfonyl or C1 -C4 -alkylsulfonyl, P is 1 or 2 and A is a radical of the formula STR2 in which: the groups designated "alk" are independently of each other straight or branched polymethylene radicals having 2 to 6 carbon atoms, and Z is β-halogenoethyl, vinyl, β-sulfatoethyl, β-thiosulfatoethyl or βacetoxyethyl.
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- Reactive pyridone azo dyes having both monochlorotriazinyl and vinylsulfone type reactive groups
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A monoazo compound represented by a free acid of the formula: STR1 wherein R1 and R2 independently represent a hydrogen atom, or an alkyl, aralkyl or cyclohexyl group; R3 represents a hydrogen atom or a methyl or sulfonic acid group; R4 represents a hydrogen atom or an alkyl group; A represents an oxygen atom or --NH--; X1 and X2 independently represent a hydrogen or chlorine atom, or a methyl, methoxy, carboxyl or sulfonic acid group; and Y represents --CH=CH2 or --CH2 CH2 Z in which Z represents a halogen atom, --OSO3 H or --OPO3 H2. This compound is used for dyeing cellulose fibers to give dyed products of yellow to reddish yellow having excellent fastnesses, particularly chlorine fastness.
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- Reactive dyestuffs, their manufacture and use
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Dyestuffs of the formula STR1 wherein R1 is hydrogen or a low-molecular alkyl group, R2 is hydrogen, a low-molecular alkyl group, an aryl radical or the radical of an organic dyestuff containing sulpho groups, and R1 and R2 together with the nitrogen atom can form a ring, X1 and X2 are hydrogen, a sulpho group or the --N=N--K radical, wherein K is the radical of a coupling component and, if one X is the --N=N--K radical, the other X is a sulpho group, and the benzene ring A can contain further substituents.
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- Process for monoacylating water-soluble organic amino compounds
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A process for the monoacylation of water-soluble organic amino compounds with 2,4,6-trifluoro-s-triazine, which comprises introducing all reactants simultaneously and continuously in the amounts necessary for the required throughput into the reaction space and removing the resultant reaction products continuously therefrom.
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- Water-soluble azo dyestuffs containing triazine and 3-azo-2,6-dihydroxypyrid-6-one radicals
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A new class of cellulose reactive dyes have a sulphonated benzene, naphthalene or naphthalene azobenzene diazo component coupled on to a class of coupling components of the formula: SPC1 In which T1 is H, monocyclic aryl, OH, CO2 H, aminocarbonyl, lower alkyl, lower alkoxy and lower alkoxycarbonyl, T2 is H, CO2 H, lower alkyl, lower alkoxy, monocyclic aryl, benzyl, aminocarbonyl and lower alkoxycarbonyl, the diazo component carrying a cellulose-reactive group. Also included are dyes in which two moles of such a monoazo dye are linked through a diamine radical. Cr and Co complexes of dyes in which the diazo component is a o-aminophenol or o-aminonaphthol are included. These dyes are usefully employed to color cellulose, wool or polyamide textile materials. These dyes impart to the textile materials deep shades having excellent fastness to light and to the wet treatments which are commonly applied to cellulose textile materials.
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- Triazine dyestuffs
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Reactive azine dyestuffs of the formula: SPC1 Wherein Am is selected from a group consisting of anilino, di(lower alkyl)amino and N(lower alkyl)benzylamino radicals, one of Y1 and Y2 is H or SO3 H and the other is H or an alkyl or alkoxy group of 1-4 carbon atoms, One of X1 or X2 is H, SO3 H, --SO2 CH2 CH2 OSO3 H or --SO2 CH=CH2 and the other is H, an alkyl or alkoxy group of 1-4 carbon atoms, Cl or CO2 H, X3 is H, an alkyl group of 1-4 carbon atoms or SO3 H, when the dotted fused ring is present B is absent and when the dotted fused ring is absent B is H or an alkyl or alkoxy group of 1-4 carbon atoms, At least one of the pendant benzene nuclei contains a NHQ group where Q is a cellulose-reactive group except when X1 or X2 is --SO2 CH2 CH2 OSO3 H or --SO2 CH=CH2 and the dyestuff as a whole contains at least 2 sulphonic acid groups. The products are reactive dyes for cellulose which are colored in strong bright blue or reddish-blue shades of excellent fastness to washing and of a reasonable fastness to light, especially in respect of wet fading.
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