[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was synthesized,using tert-butyldimethylsilane(TBDMS)and 1,2-epoxy-4-vinylcyclohexane(EVC)as the main raw materials and tris(triphenylphosphine)chlororhodium(I)[...[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was synthesized,using tert-butyldimethylsilane(TBDMS)and 1,2-epoxy-4-vinylcyclohexane(EVC)as the main raw materials and tris(triphenylphosphine)chlororhodium(I)[RhCl(Ph3P)3]as the catalyst.[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane is a novel kind of silicon-containing epoxide.The factors affecting the reaction yield,such as catalyst use,reaction time and reaction temperature,were investigated,and the synthesized product was characterized and analyzed by FT-IR and 1H-NMR.A series of amine-curing resins were prepared with[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane,bisphenol A epoxy resin(E-51)and modified amine(593 amine).The mechanical properties of cured splines with the different proportions of amine-curing resins were tested.When the content of 593 amine was 20%,the content of E-51 was 75%and the amount of[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was 5%,the mechanical properties of the cured splines were the best with the tensile strength being 23.3 MPa,the elongation at break being 7.8%,and the Young's modulus being 421.3 MPa.展开更多
Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sic...Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sichuan University(SCU-PSI).The properties of the contaminated films on the surface of pristine and He-plasma pre-irradiated tungsten matrix,such as morphology,crystalline structure,element composition and chemical structure were characterized by scanning electron microscopy,grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy.The experimental results revealed that the removal of C–N film with a thickness of tens of microns can be realized through APPJ cleaning regardless of the morphology of the substrates.Similar removal rates of 16.82 and 13.78μm min^(-1)were obtained for C–N films deposited on a smooth pristine W surface and rough fuzz-covered W surface,respectively.This is a remarkable improvement in comparison to the traditional cleaning method.However,slight surface oxidation was found after APPJ cleaning,but the degree of oxidation was acceptable with an oxidation depth increase of only 3.15 nm.Optical emission spectroscopy analysis and mass spectrometry analysis showed that C–N contamination was mainly removed through chemical reaction with reactive oxygen species during APPJ treatment using air as the working gas.These results make APPJ cleaning a potentially effective method for the rapid removal of C–N films from the wall surfaces of fusion devices.展开更多
The mechanisms of action on monofunctional guanine adducts of analogues of transplatin with aliphatic amine ligands,such as trans-[Pt（Am）（isopropylamine）（G）（H2O）] where Am represents dimethylamine,propylamine ...The mechanisms of action on monofunctional guanine adducts of analogues of transplatin with aliphatic amine ligands,such as trans-[Pt（Am）（isopropylamine）（G）（H2O）] where Am represents dimethylamine,propylamine or isopropylamine and their cis isomers reacting with sulfur- and nitrogen-containing amino acid residues,were explored. Histidine and lysine residues are chosen as the model ligands of nitrogen-containing amino acid residues of proteins; meanwhile,methionine and cysteine residues are chosen as the model ligands of sulfur-containing amino acid residues of proteins. A dominating preference for sulfur-containing ligand over nitrogen-containing ligand is established. The calculated smallest activation barrier for sulfur-containing ligand is 9.9,and 21.1 kcal/mol for nitrogen-containing ligand in aqueous solution,and both of them have trans configurations. The difference in activation energy is 11.2 kcal/mol,indicating the platination of sulfur-containing amino acid residues is faster by seven to eight orders of magnitude than that of nitrogen-containing amino acid residues.展开更多
A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the ...A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the reaction step and atom economy. It has been investigated that the 2,4,6-trimethylpyridine ligand was critical to achieve the optimized reactivity. This protocol provides a straightforward route for synthesizing the alkynylated free benzylamines, featuring good substrate compatibility and monoselectivity.展开更多
The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the i...The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the issues,a novel pentamethyldiethylenetriamine(PMDETA)-2-amino-2-methyl-1-propanol(AMP)/diethylenetriamine(DETA)-sulfolane biphasic solvent was developed.The mechanism of AMP affecting CO_(2) recycling capacity was analyzed.By adjusting the ratio of AMP and DETA,the absorption and desorption performance were balanced,and the recycling capacity and renewable energy consumption of the absorbent were improved.For the P_(2.4)A_(0.8)D_(0.8)S_(2) biphasic solvent,the CO_(2) loading of the rich phase was 5.87 mol/L,and the proportion of the rich phase volume ratio was 35%,which surpasses most reported biphasic solvents.The viscosity of the absorbent significantly decreased from 527.00 mPa·s to 92.26 mPa·s,attributed to the beneficial effect of AMP.Thermodynamic analysis showed that the biphasic solvent produced a lower regeneration energy consumption of 1.70 GJ/t CO_(2),which was 57%lower than that of monoethanolamine(MEA).Overall,the PMDETA-AMP/DETA-sulfolane biphasic solvent exhibited cycle capacity,which provided new insights for the designing of biphasic solvent.展开更多
N-substituted furfurylamines(FAs)are valuable precursors for producing pharmacologically active compounds and polymers.However,enzymatic synthesis of the type of chemicals is still in its infancy.Here we report an imi...N-substituted furfurylamines(FAs)are valuable precursors for producing pharmacologically active compounds and polymers.However,enzymatic synthesis of the type of chemicals is still in its infancy.Here we report an imine reductase from Streptomyces albidoflavus(SaIRED)for the reductive amination of biobased furans.A simple,fast and interference-resistant high-throughput screening(HTS)method was developed,based on the coloration reaction of carbonyl compounds with 2,4-dinitrophenylhydrazine.The reductive amination activity of IREDs can be directly indicated by a colorimetric assay.With the reductive amination of furfural with allylamine as the model reaction,SaIRED with the activity of 4.8 U mg^(-1) was subjected to three rounds of protein engineering and screening by this HTS method,affording a high-activity tri-variant I127V/D241A/A242T(named M3,20.2 U mg^(-1)).The variant M3 showed broad substrate scope,and enabled efficient reductive amination of biobased furans with a variety of amines including small aliphatic amines and sterically hindered amines,giving the target FAs in yields up to>99%.In addition,other variants were identified for preparative-scale synthesis of commercially interesting amines such as N-2-(methylsulfonyl)ethyl-FA by the screen method,with isolated yields up to 87%and turnover numbers up to 9700 for enzyme.Gram-scale synthesis of N-allyl-FA,a valuable building block and potential polymer monomer,was implemented at 0.25 mol L^(-1) substrate loading by a whole-cell catalyst incorporating variant M3,with 4.7 g L^(-1) h^(-1) space-time yield and 91%isolated yield.展开更多
An electronic circular dichroism(ECD)-based chiroptical sensing method has been developed forβ-andγ-chiral primary amines via a C-H activation reaction.With the addition of Pd(OAc)_(2),the flexible remote chiral pri...An electronic circular dichroism(ECD)-based chiroptical sensing method has been developed forβ-andγ-chiral primary amines via a C-H activation reaction.With the addition of Pd(OAc)_(2),the flexible remote chiral primary amine fragment in the bidentate ligand intermediate was fixed to form a cyclopalladium complex,producing an intense ECD response.The correlation between the sign of Cotton effects and the absolute configuration of substrates was proposed,together with theoretical verification using timedependent density functional theory(TDDFT).Chiroptical sensing of an important drug raw material was performed to provide rapid and accurate information on the absolute optical purity.This work introduces an alternative perspective of C-H activation reaction as well as a feasible chiroptical sensing method of remote chiral amines.展开更多
The collecting power of tertiary amines（DRN,DEN and DPN） on kaolinite follows the order of DENDPNDRN.After reacting with DRN,DEN and DPN,the surface potentials of kaolinite increase remarkably,and the recruitments c...The collecting power of tertiary amines（DRN,DEN and DPN） on kaolinite follows the order of DENDPNDRN.After reacting with DRN,DEN and DPN,the surface potentials of kaolinite increase remarkably,and the recruitments caused by collectors also follow the order of DENDPNDRN.The results of dynamics simulation show that the geometries of substituent groups bonding to N are deflected and twisted,and some of bond angles are changed when tertiary amines cations adsorb on kaolinite（001） surface.Based on the results of dynamics simulations and quantum chemistry calculations,the electrostatic forces between three tertiary amines cations and 4×4×3（001） plane of kaolinite are 1.38×10？7 N（DRN12H＋）,1.44×10-6 N（DEN12H＋）,1.383×10-6 N（DPN12H＋）,respectively.展开更多
The formation of toxic nitrogenous disinfection byproducts （N-DBPs）, such as nitrosamines, halonitromethanes and haloacetonitriles, from reactions between chlorine/chloramine and dissolved organic nitrogen in drinki...The formation of toxic nitrogenous disinfection byproducts （N-DBPs）, such as nitrosamines, halonitromethanes and haloacetonitriles, from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health. This study revealed the occurrence of 17 aliphatic amines, some of which have been confirmed to be the precursors of N-DBPs, in source water across China. A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples. In total, 37 source water samples from the capital cities of 20 provinces were collected for the survey. Among the 17 amines, 14 were detected with an average frequency of detection of 36%. The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine （100%, 24.82 μg/L）, methylamine （78%, 0.92 μg/L）, N-methylethylamine （70%, 8.84 μg/L）, propylamine （59%, 10.69 μg/L）, diethylamine （54%, 3.76μg/L）, N-methylbutylamine （35%, 3.07 μg/L）, N-ethylpropylamine （35%, 0.52μg/L）, and piperidine （32%, 2.35 μg/L）. This is the first large scale survey of the aliphatic amines occurrence in source water in the world. The wide presence of nitrosamine precursors like dimethylamine, N-methylethylamine and diethylamine, and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.展开更多
The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differential scanning calorimetry （DSC）. Th...The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differential scanning calorimetry （DSC）. The results showed that the modified dicyandiamide had better curing characteristic than unmodified dicyandiamide for epoxy resin E-44, and the curing reaction could be carried out at moderate temperature. Apparent activation energy of the curing reaction was decreased appreciably from 123.829 kJ/mol to 61.550-64.405 kJ/mol, and reaction order was decreased from 0.941 to 0.896-0.900. Curing reaction mechanism also was discussed.展开更多
A novel system was proposed for the capture and separation of CO 2 from flue gas. In this method, a resin was employed to regenerate the amine capturing CO 2 from flue gas at room temperature. The feasibility for ...A novel system was proposed for the capture and separation of CO 2 from flue gas. In this method, a resin was employed to regenerate the amine capturing CO 2 from flue gas at room temperature. The feasibility for the resin to regenerate amines such as MEA, MAE, TEA, and ammonia was demonstrated. It was also discovered that the resin could be regenerated by hot water.展开更多
In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4...In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid （IL） phase was injected directly into the high performance liquid chromatography （HPLC） system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection （LOD, S/N = 3） for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations （R.S.D., n = 6） were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.展开更多
Ru(bpy)3]2+-cored supramolecular organic framework SMOF-1, assembled from a [Ru(bpy)3]2+-derived hexaarmed molecule and cucurbit[8]uril, has been demonstrated to heterogeneously catalyze visible light-induced reductio...Ru(bpy)3]2+-cored supramolecular organic framework SMOF-1, assembled from a [Ru(bpy)3]2+-derived hexaarmed molecule and cucurbit[8]uril, has been demonstrated to heterogeneously catalyze visible light-induced reduction of phenyl, benzyl, 2-phenylethyl and 3-phenylpropyl azides in acetonitrile to produce the corresponding amines in good to high yields. For the last two kinds of azides that bear a CO2Me group at the para-position of the benzene ring, cascade reactions take place to generate the corresponding lactams in high yields. Compared with homogeneous control [Ru(bpy)3]Cl2, SMOF-1 exhibits remarkably increased photocatalysis activity as a result of synergistic effect of the [Ru(bpy)3]2+ units that form cubic cages to host the azide molecules and related intermediates. Moreover, SMOF-1 displays high recyclability and considerable photocatalysis activity after 3 to 12 runs.展开更多
N-Arylation of a wide variety of amines with phenylboronic acid catalyzed by copper acetate under 20%aqueous solution of n-Bu_4NOH was accomplished in good to excellent yields（up to 92%） and substrate conversions（u...N-Arylation of a wide variety of amines with phenylboronic acid catalyzed by copper acetate under 20%aqueous solution of n-Bu_4NOH was accomplished in good to excellent yields（up to 92%） and substrate conversions（up to 96%）.展开更多
Semi-empirical molecular orbital calculations were performed on heterocyclic aromatic amines(HCAs). The relationship between the structures and the carcinogenicities can be rationally elucidated by the models based on...Semi-empirical molecular orbital calculations were performed on heterocyclic aromatic amines(HCAs). The relationship between the structures and the carcinogenicities can be rationally elucidated by the models based on the metabolism of HCAs and the Di-region theory. The degree of easiness for the formation of Di-region electrophilic centers determines the carcinogenic activity. There is a good linear relationship between the observed carcinogenicities and the PM3 calculated parameters, with r=0.973 and F=29.8>F ** 0.01 .展开更多
Presented in several types of food, bioactive amines are described as organic bases of low molecular weight. They have vasoactive, psychoactive and toxicological characteristics and constitute a potential health risk....Presented in several types of food, bioactive amines are described as organic bases of low molecular weight. They have vasoactive, psychoactive and toxicological characteristics and constitute a potential health risk. The concentration of amines formed in foods depends on the type of microorganisms present, the action of decarboxylase enzymes produced by microorganisms on specific amino acids and favorable conditions for enzymatic activity. The presence of these chemical metabolites has been suggested as a quality indicator in routine analyzes for food production and marketing monitoring. The detection of bioactive amines can be performed by chromatographic methods, fluorometric and enzymatic kits. Bioactive amine formation can be prevented mainly through the adoption of good manufacturing practices, but the industry can also use other methods such as temperature control in the production chain, modified atmosphere packaging and food irradiation. This review aims to address the formation of bioactive amines in foods, emphasizing the formation and classification of these metabolites, aspects related to health, acceptable limits, detection methods and control methods used in the industry to ensure food safety and quality. The success of this approach is linked to the importance of bioactive amines as quality indicators, as well as the discussion on the development of methodologies for determining these substances and discussion of acceptable parameters in food.展开更多
In this work, supramolecular fixation of three amines, including aniline, ethylenediamine, and diethylamine, using cobalt tetraphenylporphyrin （CoTPP） for SO2 removal was studied using UV-Vis and fluorescence measur...In this work, supramolecular fixation of three amines, including aniline, ethylenediamine, and diethylamine, using cobalt tetraphenylporphyrin （CoTPP） for SO2 removal was studied using UV-Vis and fluorescence measurements. The UV-Vis spectra showed that increasing amines concentrations resulted in bathochromic shift for CoTPP Soret absorption band （B band）. Once SO2 was introduced, it competed with CoTPP for aniline, ethylenediamine, and diethylamine, which eventually led to the release of CoTPP and the change of solution colour/absorption band. After that, the CoTPP was regenerated and got back to the first state. The fluorescence spectra offered that CoTPP interacted with aniline, ethylenediamine, and diethylamine to form 1：1 molecular adducts. The interactions of CoTPP with aniline, ethylenediamine, and diethylamine were entropy-driven. The interaction of CoTPP with aniline and diethylamine was endothermic, and that with ethylenediamine was exothermic. Ethylenediamine presented a stronger binding constant value for CoTPP, so it was considered as a potential agent for SO2 removal.展开更多
Carbamates are important intermediates in the syntheses of pesticides, herbicides, drugs, polyurethane-based polymers, and other fine and commodity chemicals.
The regulation of three biogenic amines over the reproductive neuroendoerine activity of the male Scylla serrata was investigated by in vivo injection and in vitro incubation. The testicular index, the ratio of the ma...The regulation of three biogenic amines over the reproductive neuroendoerine activity of the male Scylla serrata was investigated by in vivo injection and in vitro incubation. The testicular index, the ratio of the mature sections in testes, and the ratio of Type B cells in androgenic gland were taken as the quantitative indexes. The in vivo injections indicated that： 5-HT can significantly promote the testicular development and the secretion of the androgenic gland in S. serrata; DA can inhibit the testicular development, but no influence on the secretion of the androgenic gland was found; no significant difference was observed between the OA-injected group and the concurrent control group. In vitro incubations showed that： 5-HT can stimulate the secretion of the brain and the thoracic ganglia, thus accelerating that of the androgenic gland; however, neither OA nor DA showed any significant influence on the secretion of the brain and the thoracic ganglionic mass. As to the optic ganglia, the three biogenic amines hardly have any effect on its secretion. It is the first time to report the regulation of biogenic amines over the reproductive neuroendocrine of male crustaceans through vitro experiments. Results corroborate that 5-HT activates the brain and the thoracic ganglia to secret GSH first, then promote the testicular development through the activity of the androgenic gland.展开更多
The effect of chloride ion on the corrosion inhibition of iron caused by dencylamine(DA), dipentylamine(DDA) and dodecylamine(DPA) has been investigated by measuring the inhibitory coefficients for the anodic and cath...The effect of chloride ion on the corrosion inhibition of iron caused by dencylamine(DA), dipentylamine(DDA) and dodecylamine(DPA) has been investigated by measuring the inhibitory coefficients for the anodic and cathodic processes at corrosion potential. It has been shown that the major synergistic inhibition effects between amines and chloride ions occur in the cathodic process, very weak in the anodic process. The anodic inhibition mechanism follows the competing adsorptive model, while the cathodic inhibition mechanism follows the cooperative adsorptive model.展开更多
基金Funded by the National Natural Science Foundation of China(No.21865017)。
文摘[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was synthesized,using tert-butyldimethylsilane(TBDMS)and 1,2-epoxy-4-vinylcyclohexane(EVC)as the main raw materials and tris(triphenylphosphine)chlororhodium(I)[RhCl(Ph3P)3]as the catalyst.[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane is a novel kind of silicon-containing epoxide.The factors affecting the reaction yield,such as catalyst use,reaction time and reaction temperature,were investigated,and the synthesized product was characterized and analyzed by FT-IR and 1H-NMR.A series of amine-curing resins were prepared with[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane,bisphenol A epoxy resin(E-51)and modified amine(593 amine).The mechanical properties of cured splines with the different proportions of amine-curing resins were tested.When the content of 593 amine was 20%,the content of E-51 was 75%and the amount of[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was 5%,the mechanical properties of the cured splines were the best with the tensile strength being 23.3 MPa,the elongation at break being 7.8%,and the Young's modulus being 421.3 MPa.
基金funded by National Key Research, Development Program of China (No. 2017YFE0301305KYWX-002)Sichuan Science and Technology Program (No. 2021YFSY0015)
文摘Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sichuan University(SCU-PSI).The properties of the contaminated films on the surface of pristine and He-plasma pre-irradiated tungsten matrix,such as morphology,crystalline structure,element composition and chemical structure were characterized by scanning electron microscopy,grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy.The experimental results revealed that the removal of C–N film with a thickness of tens of microns can be realized through APPJ cleaning regardless of the morphology of the substrates.Similar removal rates of 16.82 and 13.78μm min^(-1)were obtained for C–N films deposited on a smooth pristine W surface and rough fuzz-covered W surface,respectively.This is a remarkable improvement in comparison to the traditional cleaning method.However,slight surface oxidation was found after APPJ cleaning,but the degree of oxidation was acceptable with an oxidation depth increase of only 3.15 nm.Optical emission spectroscopy analysis and mass spectrometry analysis showed that C–N contamination was mainly removed through chemical reaction with reactive oxygen species during APPJ treatment using air as the working gas.These results make APPJ cleaning a potentially effective method for the rapid removal of C–N films from the wall surfaces of fusion devices.
文摘The mechanisms of action on monofunctional guanine adducts of analogues of transplatin with aliphatic amine ligands,such as trans-[Pt（Am）（isopropylamine）（G）（H2O）] where Am represents dimethylamine,propylamine or isopropylamine and their cis isomers reacting with sulfur- and nitrogen-containing amino acid residues,were explored. Histidine and lysine residues are chosen as the model ligands of nitrogen-containing amino acid residues of proteins; meanwhile,methionine and cysteine residues are chosen as the model ligands of sulfur-containing amino acid residues of proteins. A dominating preference for sulfur-containing ligand over nitrogen-containing ligand is established. The calculated smallest activation barrier for sulfur-containing ligand is 9.9,and 21.1 kcal/mol for nitrogen-containing ligand in aqueous solution,and both of them have trans configurations. The difference in activation energy is 11.2 kcal/mol,indicating the platination of sulfur-containing amino acid residues is faster by seven to eight orders of magnitude than that of nitrogen-containing amino acid residues.
基金supported financially by the Excellent Going Abroad Expert's Training Program in Hebei Province (No. 201940)the Hebei Natural Science Foundation of China (No. H2020208030)the S & T Program of Hebei (No. 22567607H) for financial support。
文摘A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the reaction step and atom economy. It has been investigated that the 2,4,6-trimethylpyridine ligand was critical to achieve the optimized reactivity. This protocol provides a straightforward route for synthesizing the alkynylated free benzylamines, featuring good substrate compatibility and monoselectivity.
基金supported by the Key R&D Program of Yunnan Province(No.202303AC100008)the National Natural Science Foundation of China(No.52100133)the Major Science and Technology-Special Plan“Unveiling and Leading”Project of Shanxi Province(No.202201050201011).
文摘The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the issues,a novel pentamethyldiethylenetriamine(PMDETA)-2-amino-2-methyl-1-propanol(AMP)/diethylenetriamine(DETA)-sulfolane biphasic solvent was developed.The mechanism of AMP affecting CO_(2) recycling capacity was analyzed.By adjusting the ratio of AMP and DETA,the absorption and desorption performance were balanced,and the recycling capacity and renewable energy consumption of the absorbent were improved.For the P_(2.4)A_(0.8)D_(0.8)S_(2) biphasic solvent,the CO_(2) loading of the rich phase was 5.87 mol/L,and the proportion of the rich phase volume ratio was 35%,which surpasses most reported biphasic solvents.The viscosity of the absorbent significantly decreased from 527.00 mPa·s to 92.26 mPa·s,attributed to the beneficial effect of AMP.Thermodynamic analysis showed that the biphasic solvent produced a lower regeneration energy consumption of 1.70 GJ/t CO_(2),which was 57%lower than that of monoethanolamine(MEA).Overall,the PMDETA-AMP/DETA-sulfolane biphasic solvent exhibited cycle capacity,which provided new insights for the designing of biphasic solvent.
文摘N-substituted furfurylamines(FAs)are valuable precursors for producing pharmacologically active compounds and polymers.However,enzymatic synthesis of the type of chemicals is still in its infancy.Here we report an imine reductase from Streptomyces albidoflavus(SaIRED)for the reductive amination of biobased furans.A simple,fast and interference-resistant high-throughput screening(HTS)method was developed,based on the coloration reaction of carbonyl compounds with 2,4-dinitrophenylhydrazine.The reductive amination activity of IREDs can be directly indicated by a colorimetric assay.With the reductive amination of furfural with allylamine as the model reaction,SaIRED with the activity of 4.8 U mg^(-1) was subjected to three rounds of protein engineering and screening by this HTS method,affording a high-activity tri-variant I127V/D241A/A242T(named M3,20.2 U mg^(-1)).The variant M3 showed broad substrate scope,and enabled efficient reductive amination of biobased furans with a variety of amines including small aliphatic amines and sterically hindered amines,giving the target FAs in yields up to>99%.In addition,other variants were identified for preparative-scale synthesis of commercially interesting amines such as N-2-(methylsulfonyl)ethyl-FA by the screen method,with isolated yields up to 87%and turnover numbers up to 9700 for enzyme.Gram-scale synthesis of N-allyl-FA,a valuable building block and potential polymer monomer,was implemented at 0.25 mol L^(-1) substrate loading by a whole-cell catalyst incorporating variant M3,with 4.7 g L^(-1) h^(-1) space-time yield and 91%isolated yield.
基金supported by the CAMS Innovation Fund for Medical Sciences(CIFMS,No.2023-I2M-2-009).
文摘An electronic circular dichroism(ECD)-based chiroptical sensing method has been developed forβ-andγ-chiral primary amines via a C-H activation reaction.With the addition of Pd(OAc)_(2),the flexible remote chiral primary amine fragment in the bidentate ligand intermediate was fixed to form a cyclopalladium complex,producing an intense ECD response.The correlation between the sign of Cotton effects and the absolute configuration of substrates was proposed,together with theoretical verification using timedependent density functional theory(TDDFT).Chiroptical sensing of an important drug raw material was performed to provide rapid and accurate information on the absolute optical purity.This work introduces an alternative perspective of C-H activation reaction as well as a feasible chiroptical sensing method of remote chiral amines.
基金Project (2005CB623701) supported by the National Basic Research Program of China Project (201011031) supported by National Department Public Benefit Research Foundation from Ministry of Land and Resources of China+1 种基金 Project (2935) supported by the Foundation for the Author of Zhengzhou Institute of Multipurpose Utilization of Mineral Resources CAGS, China Project (1212011120304) supported by the Geological Surrey Program
文摘The collecting power of tertiary amines（DRN,DEN and DPN） on kaolinite follows the order of DENDPNDRN.After reacting with DRN,DEN and DPN,the surface potentials of kaolinite increase remarkably,and the recruitments caused by collectors also follow the order of DENDPNDRN.The results of dynamics simulation show that the geometries of substituent groups bonding to N are deflected and twisted,and some of bond angles are changed when tertiary amines cations adsorb on kaolinite（001） surface.Based on the results of dynamics simulations and quantum chemistry calculations,the electrostatic forces between three tertiary amines cations and 4×4×3（001） plane of kaolinite are 1.38×10？7 N（DRN12H＋）,1.44×10-6 N（DEN12H＋）,1.383×10-6 N（DPN12H＋）,respectively.
基金supported by the National Natural Science Foundation of China (No.21077118)the National Special Funding Project for Water Pollution Control and Management of China (No.2009ZX07419-001)
文摘The formation of toxic nitrogenous disinfection byproducts （N-DBPs）, such as nitrosamines, halonitromethanes and haloacetonitriles, from reactions between chlorine/chloramine and dissolved organic nitrogen in drinking water has caused great concern with regarding public health. This study revealed the occurrence of 17 aliphatic amines, some of which have been confirmed to be the precursors of N-DBPs, in source water across China. A sensitive method based on benzenesulfonyl chloride derivatization and liquid-liquid extraction followed by GC-MS analysis was established for the simultaneous analysis of the selected amines in aqueous samples. In total, 37 source water samples from the capital cities of 20 provinces were collected for the survey. Among the 17 amines, 14 were detected with an average frequency of detection of 36%. The most relevant amines in terms of frequency and maximum concentrations detected were dimethylamine （100%, 24.82 μg/L）, methylamine （78%, 0.92 μg/L）, N-methylethylamine （70%, 8.84 μg/L）, propylamine （59%, 10.69 μg/L）, diethylamine （54%, 3.76μg/L）, N-methylbutylamine （35%, 3.07 μg/L）, N-ethylpropylamine （35%, 0.52μg/L）, and piperidine （32%, 2.35 μg/L）. This is the first large scale survey of the aliphatic amines occurrence in source water in the world. The wide presence of nitrosamine precursors like dimethylamine, N-methylethylamine and diethylamine, and the precursors of haloacetonitriles and halonitromethanes like methylamine and propylamine suggests that better source water management is required to ensure the safety of drinking water.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (2003AA305920)
文摘The curing reaction and reaction mechanism of epoxy resin E-44, for which aromatic amine modified dicyandiamide was used as a curing reagent, were investigated by means of differential scanning calorimetry （DSC）. The results showed that the modified dicyandiamide had better curing characteristic than unmodified dicyandiamide for epoxy resin E-44, and the curing reaction could be carried out at moderate temperature. Apparent activation energy of the curing reaction was decreased appreciably from 123.829 kJ/mol to 61.550-64.405 kJ/mol, and reaction order was decreased from 0.941 to 0.896-0.900. Curing reaction mechanism also was discussed.
文摘A novel system was proposed for the capture and separation of CO 2 from flue gas. In this method, a resin was employed to regenerate the amine capturing CO 2 from flue gas at room temperature. The feasibility for the resin to regenerate amines such as MEA, MAE, TEA, and ammonia was demonstrated. It was also discovered that the resin could be regenerated by hot water.
基金the National Natural Science Foundation of China(Nos.20375035,20527005,20775070)by Zhejiang Provincial Natural Science Foundation of China(Nos.Z404105,Y507252).
文摘In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction （IL-DLLME） was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid （IL） phase was injected directly into the high performance liquid chromatography （HPLC） system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection （LOD, S/N = 3） for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations （R.S.D., n = 6） were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.
基金supported by the National Natural Science Foundation of China (Nos. 21432004 and 21890732)
文摘Ru(bpy)3]2+-cored supramolecular organic framework SMOF-1, assembled from a [Ru(bpy)3]2+-derived hexaarmed molecule and cucurbit[8]uril, has been demonstrated to heterogeneously catalyze visible light-induced reduction of phenyl, benzyl, 2-phenylethyl and 3-phenylpropyl azides in acetonitrile to produce the corresponding amines in good to high yields. For the last two kinds of azides that bear a CO2Me group at the para-position of the benzene ring, cascade reactions take place to generate the corresponding lactams in high yields. Compared with homogeneous control [Ru(bpy)3]Cl2, SMOF-1 exhibits remarkably increased photocatalysis activity as a result of synergistic effect of the [Ru(bpy)3]2+ units that form cubic cages to host the azide molecules and related intermediates. Moreover, SMOF-1 displays high recyclability and considerable photocatalysis activity after 3 to 12 runs.
文摘N-Arylation of a wide variety of amines with phenylboronic acid catalyzed by copper acetate under 20%aqueous solution of n-Bu_4NOH was accomplished in good to excellent yields（up to 92%） and substrate conversions（up to 96%）.
基金the National Natural Science Foundation of China(No.2 0 0 4 2 0 0 1) and by the Postdoctoral Foundation ofthe Ministry of Education P.R.China
文摘Semi-empirical molecular orbital calculations were performed on heterocyclic aromatic amines(HCAs). The relationship between the structures and the carcinogenicities can be rationally elucidated by the models based on the metabolism of HCAs and the Di-region theory. The degree of easiness for the formation of Di-region electrophilic centers determines the carcinogenic activity. There is a good linear relationship between the observed carcinogenicities and the PM3 calculated parameters, with r=0.973 and F=29.8>F ** 0.01 .
文摘Presented in several types of food, bioactive amines are described as organic bases of low molecular weight. They have vasoactive, psychoactive and toxicological characteristics and constitute a potential health risk. The concentration of amines formed in foods depends on the type of microorganisms present, the action of decarboxylase enzymes produced by microorganisms on specific amino acids and favorable conditions for enzymatic activity. The presence of these chemical metabolites has been suggested as a quality indicator in routine analyzes for food production and marketing monitoring. The detection of bioactive amines can be performed by chromatographic methods, fluorometric and enzymatic kits. Bioactive amine formation can be prevented mainly through the adoption of good manufacturing practices, but the industry can also use other methods such as temperature control in the production chain, modified atmosphere packaging and food irradiation. This review aims to address the formation of bioactive amines in foods, emphasizing the formation and classification of these metabolites, aspects related to health, acceptable limits, detection methods and control methods used in the industry to ensure food safety and quality. The success of this approach is linked to the importance of bioactive amines as quality indicators, as well as the discussion on the development of methodologies for determining these substances and discussion of acceptable parameters in food.
文摘In this work, supramolecular fixation of three amines, including aniline, ethylenediamine, and diethylamine, using cobalt tetraphenylporphyrin （CoTPP） for SO2 removal was studied using UV-Vis and fluorescence measurements. The UV-Vis spectra showed that increasing amines concentrations resulted in bathochromic shift for CoTPP Soret absorption band （B band）. Once SO2 was introduced, it competed with CoTPP for aniline, ethylenediamine, and diethylamine, which eventually led to the release of CoTPP and the change of solution colour/absorption band. After that, the CoTPP was regenerated and got back to the first state. The fluorescence spectra offered that CoTPP interacted with aniline, ethylenediamine, and diethylamine to form 1：1 molecular adducts. The interactions of CoTPP with aniline, ethylenediamine, and diethylamine were entropy-driven. The interaction of CoTPP with aniline and diethylamine was endothermic, and that with ethylenediamine was exothermic. Ethylenediamine presented a stronger binding constant value for CoTPP, so it was considered as a potential agent for SO2 removal.
文摘Carbamates are important intermediates in the syntheses of pesticides, herbicides, drugs, polyurethane-based polymers, and other fine and commodity chemicals.
基金supported by the National Natural Science Foundation of China under contract No.30300269the National High Technology Research and Development Program("863"program)of China under contract No.2002AA603013.
文摘The regulation of three biogenic amines over the reproductive neuroendoerine activity of the male Scylla serrata was investigated by in vivo injection and in vitro incubation. The testicular index, the ratio of the mature sections in testes, and the ratio of Type B cells in androgenic gland were taken as the quantitative indexes. The in vivo injections indicated that： 5-HT can significantly promote the testicular development and the secretion of the androgenic gland in S. serrata; DA can inhibit the testicular development, but no influence on the secretion of the androgenic gland was found; no significant difference was observed between the OA-injected group and the concurrent control group. In vitro incubations showed that： 5-HT can stimulate the secretion of the brain and the thoracic ganglia, thus accelerating that of the androgenic gland; however, neither OA nor DA showed any significant influence on the secretion of the brain and the thoracic ganglionic mass. As to the optic ganglia, the three biogenic amines hardly have any effect on its secretion. It is the first time to report the regulation of biogenic amines over the reproductive neuroendocrine of male crustaceans through vitro experiments. Results corroborate that 5-HT activates the brain and the thoracic ganglia to secret GSH first, then promote the testicular development through the activity of the androgenic gland.
文摘The effect of chloride ion on the corrosion inhibition of iron caused by dencylamine(DA), dipentylamine(DDA) and dodecylamine(DPA) has been investigated by measuring the inhibitory coefficients for the anodic and cathodic processes at corrosion potential. It has been shown that the major synergistic inhibition effects between amines and chloride ions occur in the cathodic process, very weak in the anodic process. The anodic inhibition mechanism follows the competing adsorptive model, while the cathodic inhibition mechanism follows the cooperative adsorptive model.
