3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH...3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.展开更多
Density functional theory B3LYP is employed to obtain the optimized geometries of the ground state and interaction energy for triazines and water complexes. The results show that the 1,2,3-triazine-water, 1,2,4-triazi...Density functional theory B3LYP is employed to obtain the optimized geometries of the ground state and interaction energy for triazines and water complexes. The results show that the 1,2,3-triazine-water, 1,2,4-triazine-water and 1,3,5-triazine-water complex on the ground state have Cs, Cs and C1 symmetry, and strong hydrogen bonding interaction with ?17.83, ?17.38 and ?13.55 kJ/mol after basis set superposition error and zero-point vibration energy correction, respectively, and large red-shift for the symmetric H─O stretching vibration frequencies forming N···H─O hydrogen bond in the triazines complex. The first singlet (n, π*) vertical excitation energy of the monomer and the hydrogen bonding complexes between triazines and water is investigated by time-dependent density functional theory.展开更多
As a continuation of the studies on the interference of metabolism of nucleic acids by 1,2,4-triazine derivatives, we have studied the preparation and chemical properties of a number of 1,2,4-triazines.
FOR the purpose of finding novel antitumor and antivirus medicines and understanding themechanism of the metabolic process involved,several 6-azapurine derivatives were synthe-sized from 1,2,4-triazines.Mass spectrome...FOR the purpose of finding novel antitumor and antivirus medicines and understanding themechanism of the metabolic process involved,several 6-azapurine derivatives were synthe-sized from 1,2,4-triazines.Mass spectrometry plays a key role in the structure展开更多
A number of azacalix[2]pyrimidine[2]triazines were synthesized in moderate to good yields from both a step-wise fragment coupling approach and a one-pot reaction strategy starting from 4,6-diaminopyrimidines and cyanu...A number of azacalix[2]pyrimidine[2]triazines were synthesized in moderate to good yields from both a step-wise fragment coupling approach and a one-pot reaction strategy starting from 4,6-diaminopyrimidines and cyanuric chloride.Nucleophilic aromatic substitution reaction of resulting dichloro-substituted azacalix[2]-pyrimidine[2]triazines with NH_(4)Cl led to the formation of NH_(2)-bearing azacalix[2]pyrimidine[2]triazine analogs.Azacalix[2]pyrimidine[2]triazines adopted symmetric 1,3-alternate conformations in solution while twisted 1,3-alternate conformations were observed in the solid state.In the presence of different additives during the growth of single crystals,azacalix[2]pyrimidine[2]triazines containing amino(-NH_(2))groups gave varied self-assembled structures due to the formation of different intermolecular hydrogen bond motifs.展开更多
The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6(7H)-ones af...The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6(7H)-ones afforded novel dispiro[acenaphthylene-1,2’-pyrrolidine]-3',7″-[1,3]thiazolo[3,2-a][1,3,5]triazines in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis and X-ray crystallographic analysis. The results of experiment indicated that this 1,3-dipolar cycloaddition proceeded with high stereoselectivity and regioselectivity.展开更多
Carbon super-heterostructures with high nitrogen contents from the covalent hybrid precursors of covalent triazine frameworks(CTFs)and zeolitic imidazolic frameworks(ZIFs)are scarcely explored because of CTF's ord...Carbon super-heterostructures with high nitrogen contents from the covalent hybrid precursors of covalent triazine frameworks(CTFs)and zeolitic imidazolic frameworks(ZIFs)are scarcely explored because of CTF's ordered structure and toxic superacid that dissolves or destabilizes the metal nodes.To solve this problem,herein,we report a straightforward two-step pathway for the covalent hybridization of disordered CTF(d–CTF)–ZIF composites via preincorporation of an imidazole(IM)linker into ordered CTFs,followed by the imidazole-site-specific covalent growth of ZIFs.Direct carbonization of these synthesized d–CTF−IM−ZIF hybrids results in unique hollow carbon super-heterostructures with ultrahigh nitrogen content(>18.6%),high specific surface area(1663m^(2)g^(−1)),and beneficial trace metal(Co/Zn NPs)contents for promoting the redox pseudocapacitance.As proof of concept,the obtained carbon super-heterostructure(Co–Zn–NC_(SNH)–800)is used as a positive electrode in an asymmetric supercapacitor,demonstrating a remarkable energy density of 61Wh kg^(−1)and extraordinary cyclic stability of 97%retention after 30,000 cycles at the cell level.Our presynthetic modifications of CTF and their covalent hybridization with ZIF crystals pave the way toward new design strategies for synthesizing functional porous carbon materials for promising energy applications.展开更多
Porous polymer(pyrrolopyrrole)was successfully prepared via domino-ring-formation reaction.The chemical-physical properties of cyanided covalent triazine frameworks(CTF-CN)were characteriazed by fourier transform infr...Porous polymer(pyrrolopyrrole)was successfully prepared via domino-ring-formation reaction.The chemical-physical properties of cyanided covalent triazine frameworks(CTF-CN)were characteriazed by fourier transform infrared spectra(FT-IR),scanning electron microscopy(SEM),nuclear magnetic resonance(NMR),specific surface area analyzer(BET)and thermogravimetric analysis(TGA),respectively.The experimental results of adsorption of chloranil(TCBQ)in aqueous solution indicated that CTF-CN exhibited distinctive adsorption capacity toward TCBQ owing to its large specific surface area.Specifically,the adsorption equilibrium of as-prepared polymer was executed within 5 h and the calculated adsorption capacity was 499.76 mg/g.Furthermore,the adsorption kinetics could be well defined with the linear pseudo-second-order model,which implies that the chemical interaction are relative important in the course of TCBQ removal.Finally,the current studies verify that CTF-CN has unique rigid and nano-porous framework structure,which can be employed for the treatment of a series of harmful aromatic substances.展开更多
The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include orga...The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include organochlorines, triazines, organophosphates and pyrethroids. We conducted a study on the impact of these pesticide use, in particular organochlorines and triazines, on cotton farming soils. We chose the Plateaux region (southern Togo) as the study area because of its high cotton production. Analysis was carried out on crop soil samples at the 0 - 20 cm horizon. Several pesticide residues were found: simazine (0.051 to 0.103 μg/Kg soil);atrazine (0.149 to 0.197 μg/Kg soil);lindane (0.259 to 0.672 μg/Kg soil);β-endosulfan (1.37 to 5.727 μg/Kg soil);dieldrin (0.063 to 1.16 μg/Kg soil);endrin (0.512 μg/Kg soil), Heptachlor (0.489 to 1.243 μg/Kg soil);Heptachlor epoxide (0.928 to 1.633 μg/Kg soil);[2,4'DDT] (0.257 μg/Kg soil);[4,4'DDE] (0.262 μg/Kg soil). These results show pesticide contamination of cotton farming soils.展开更多
Substituted 2-azoniaallene salts 1 are strong bifunctional electrophiles, undergo cyclization reactions furnish many series of heterocyclic compounds, where reacted with p-tolyl urea, phenyl thiourea and thiosemicarba...Substituted 2-azoniaallene salts 1 are strong bifunctional electrophiles, undergo cyclization reactions furnish many series of heterocyclic compounds, where reacted with p-tolyl urea, phenyl thiourea and thiosemicarbazone derivatives to afford triazinium salts, and converted to corresponding free bases 3, 5, 7 under treatment with Na2CO3. While triazole derivatives 8 and 9 were obtained by the reaction 2-azoniaallene salts 1 with benzohydrazide and phenyl hydrazine, respectively. Benzoxazinium salts 10 and 11 were acquired when asymmetric 2-azoniaallene salt reacted in (1:1) ratio with p-cresol and 3-methyl-1-phenyl-5-pyrazolone, respectively. The reaction of 2-azoniaallene salt with malononitrile furnished the primidinium salt 12 which underwent neutralization with Na2CO3 followed by heterocyclization with hydrazine hydrate afforded the bicyclic compound 3-aminopyrazolo[3,4-d]pyrimidine 14, which is highly reactive for nucleophilic addition to phenyl isothiocyanate to furnish thiourea derivative 15. Moreover, 14 undergo condensation with aldehydes to give imine derivatives 16a,b. All free base compounds were screened for their antimicrobial activities.展开更多
Adsorption of atrazine, prometryne and prometon was determined on six soils with different physical and chemical properties. The adsorption isotherms of three herbicides could well fit Freundlich equation. On all of s...Adsorption of atrazine, prometryne and prometon was determined on six soils with different physical and chemical properties. The adsorption isotherms of three herbicides could well fit Freundlich equation. On all of six soils, adsorption of herbicides increased in the order: atrazine ≈prometon<prometryne. This order is quite the same to the calculation result of by means of excess thermodynamic properties of triazine. The Freundlich adsorption constants, K f, showed to have good correlation with organic matter(OM%) of soils for each of these herbicides, suggesting that OM is the main factor, which dominates in the adsorption process of these triazine herbicides.展开更多
A new method for the synthesis of 4,4′,6,6′-tetra(azido)azo-1,3,5-triazine (TAAT) is described. The key intermediate 4,4′,6,6′-tetra(azido)hydrazo-1,3,5-triazine (TAHT) was synthesized by nucleophilic substitution...A new method for the synthesis of 4,4′,6,6′-tetra(azido)azo-1,3,5-triazine (TAAT) is described. The key intermediate 4,4′,6,6′-tetra(azido)hydrazo-1,3,5-triazine (TAHT) was synthesized by nucleophilic substitution in the case of sodium azide as nucleophile. N-Bromosuccinide (NBS) was used as oxidant to oxidize TAHT by a tractable operation under mild reaction condition. The target compound TAAT was obtained with a facile process and high overall yield of 81%. The structures of TAAT and its intermediates were identified by spectroscopic methods.展开更多
2D MXenes are attractive for energy storage applications because of their high electronic conductivity.However,it is still highly challenging for improving the sluggish sodium(Na)-ion transport kinetics within the MXe...2D MXenes are attractive for energy storage applications because of their high electronic conductivity.However,it is still highly challenging for improving the sluggish sodium(Na)-ion transport kinetics within the MXenes interlayers.Herein,a novel nitrogen-doped Ti3C2Tx MXene was synthesized by introducing the in situ polymeric sodium dicyanamide(Na-dca)to tune the complex terminations and then utilized as intercalation-type pseudocapacitive anode of Na-ion capacitors(NICs).The Na-dca can intercalate into the interlayers of Ti3C2 Tx nanosheets and simultaneously form sodium tricyanomelaminate(Na3TCM)by the catalyst-free trimerization.The as-prepared Ti3C2Tx/Na3TCM exhibits a high N-doping of 5.6 at.%in the form of strong Ti-N bonding and stabilized triazine ring structure.Consequently,coupling Ti3C2Tx/Na3 TCM anode with different mass of activated carbon cathodes,the asymmetric MXene//carbon NICs are assembled.It is able to deliver high energy density(97.6 Wh kg-1),high power output(16.5 kW kg-1),and excellent cycling stability(≈82.6%capacitance retention after 8000 cycles).展开更多
Potential of nanoscale triazine based dendritic macromolecules G1,G2 and G3 as solubility enhancers of drug was investigated.Effect of pH,concentration and generation of synthesized dendritic macromolecules on solubil...Potential of nanoscale triazine based dendritic macromolecules G1,G2 and G3 as solubility enhancers of drug was investigated.Effect of pH,concentration and generation of synthesized dendritic macromolecules on solubility of ketoprofen was studied.G3 dendrimer was further exploited as carrier for sustained release.Ketoprofen was encapsulated by inclusion complex method and also characterized by Flourier Transform Infrared spectroscopy.Sustained release study of ketoprofen from ketoprofen loaded dendrimer was carried out and compared with free ketoprofen.Hemolytic potential and Cytotoxicity assay using A-549 lung cancer cell lines revealed that synthesized triazine based dendritic macromolecules having more potential that commercially available PAMAM dendrimer.展开更多
A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography (MEKC) was developed. Various parameters ...A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography (MEKC) was developed. Various parameters affecting sample enrichment and separation efficiency were systematically studied. Compared with the conventional MEKC method, up to 60-200-fold improvement in concentration sensitivity was achieved in terms of peak height by using this sweeping injection technique. The compound strychnine was used as the internal standard for the improvement of the experimental reproducibility. The limits of detection (S/ N = 3:1) for atrazine, simazine and prometryn were 9, 10 and 0.5 ng mL-1, respectively. This method has been successfully applied to the analysis of atrazine, simazine and prometryn in lake, steam and ground water.展开更多
Highly porous nitrogen-doped carbon materials were synthesized by the carbonization of a low-cost porous covalent triazine polymer, PCTP-3, which had been synthesized by the AlClcatalyzed FriedelCrafts reaction of rea...Highly porous nitrogen-doped carbon materials were synthesized by the carbonization of a low-cost porous covalent triazine polymer, PCTP-3, which had been synthesized by the AlClcatalyzed FriedelCrafts reaction of readily available monomers. The nature of the bond and structure of the resulting materials were confirmed using various spectroscopic methods, and the effects of KOH activation on the textural properties of the porous carbon materials were also examined. The KOH-activated porous carbon(aPCTP-3c) materials possessed a high surface area of 2271 mgand large micro/total pore volumes of 0.87/0.95 cmg, respectively, with narrower micropore size distributions than the porous carbon prepared without activation(PCTP-3c). The aPCTP-3c exhibited the best COuptakes of 284.5 and 162.3 mg gand CHuptakes of 39.6 and 25.9 mg gat 273 and 298 K/1 bar, respectively, which are comparable to the performance of some benchmark carbon materials under the same conditions. The prepared materials exhibited high CO/Nselectivity and could be regenerated easily.展开更多
Research on water-splitting electrocatalysts is crucial to establishing a solution to the energy crisis.Herein,we report a facile bottom-up strategy for the preparation of high performance supported electrocatalysts f...Research on water-splitting electrocatalysts is crucial to establishing a solution to the energy crisis.Herein,we report a facile bottom-up strategy for the preparation of high performance supported electrocatalysts for overall water-splitting reaction via a rationally designed defect covalent triazine frameworks(CTFs)support.Specifically,defect CTFs are obtained via binary-precursor polymerization,followed by loading Ru nanoparticles(Ru/D-CTFs-900)with high HER performance at a current density of 10 mA cm-2.The overpotential is only 17 mV.Calcination of the resultant Ru–RuO2/D-CTFs-300 in air,produces excellent OER performance with 190 mV overpotential(at 10 mA cm-2).Furthermore,overall water splitting measurements reveal the potential of 1.47 V,which is better than the majority of the reported Ru-based catalysts.Moreover,density functional theory calculation results show that excellent electrocatalytic properties are attributed to the synergistic effect of Ru nanoparticles and carbon support.展开更多
Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5...Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) &ARING;, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.展开更多
Simazine and propazine are selective triazine herbicides currently in use to control broad-leaved weeds and annual grasses around the world. Bisphenol A (BPA) is an industrial chemical used in the production of polyca...Simazine and propazine are selective triazine herbicides currently in use to control broad-leaved weeds and annual grasses around the world. Bisphenol A (BPA) is an industrial chemical used in the production of polycarbonate plastics often found in consumer goods, such as plastic containers, baby bottles etc. These synthetic compounds are known to increase the risk of cancer, cause adverse reproductive effect in reptiles, mammals, birds, humans, and lead to other health problems. They have become some of the principal agents of contamination in water bodies around the world through herbicide runoff, industrial waste and leaching. Some triazines such as atrazine are banned in most European countries for over ten years due to their adverse reproductive effect in mammals, birds and humans;however propazine and simazine are still in use around the world. The removal of these compounds from contaminated water is an exigent challenge. In this study, we investigated their affinity for the surface of nanoparticles (NPS) and standard metallic oxides in an effort to exploit the unique potential applications of NPS for water purification systems. We studied the adsorption of the two triazines and BPA on the surface of NPS of iron (III) oxide, NPS of carbon, bulk iron (III) oxide and aluminum oxide at pH 6 and pH 8 using UV-Visible spectroscopy. Result indicates that these compounds have different affinity towards the surface of metallic oxides and carbon at various pHs. In general, there is relatively high adsorption of some of these compounds on the surface of NPS compared to bulk particles. NPS of carbon have shown the highest affinity for all the three compounds. The lower pH was found to be favorable for all of the compounds except for BPA. BPA have shown high adsorption at pH 8 than at pH 6.展开更多
The title compound 4-oxo-1,2,4-triazino[4,5-a]benzimidazole(C9H6N4O,Mr = 186.18) has been synthesized and structurally characterized by IR,NMR and single-crystal X-ray diffraction. The crystal belongs to monoclinic,...The title compound 4-oxo-1,2,4-triazino[4,5-a]benzimidazole(C9H6N4O,Mr = 186.18) has been synthesized and structurally characterized by IR,NMR and single-crystal X-ray diffraction. The crystal belongs to monoclinic,space group P21/c,with a = 9.1530(18) ,b = 7.2260(14),c = 12.604(3) ,β = 106.92(3) ,V = 797.5(3)A^3,Z = 4,Dc = 1.551 g/cm^3,λ(MoKa) = 0.71073,F(000) = 384,μ(MoKa) = 0.109 mm^-1,the final R = 0.0632 and wR = 0.1095. A total of 1444 unique reflections were collected,of which 767 with I 〉 2σ(I) were observed. The structure of the title compound is planar. In packing,the molecules are intersected to each other to form chains along three dimensions,together by intermolecular N-H…O and C-H…N hydrogen bonds. The whole structure is further stabilized by π…π interaction between two adjacent tricyclic ring systems,with the centroid-to-centroid distance of 3.369(4) A.展开更多
基金Director of the project supported by National Natural Science foundation of China.
文摘3-Methylthio-5-hydroxy-1,2,4-triazine(1c)reacted with substituted benzenesulfonyl chloride to give 3-methylthio-5-oxy-1,2,4-triazin-6-yl pyridinium betaine(4)in anhydrous pyridine.But when NaOH/H_2O/CH_3COCH_3 or NaOH/CH_3OH were used as reactant and solvent,3-methylthio-4-substituted benzenesulfonyl-5-oxo-6-hydroxy-1,4,5,6-tetrahydro-1,2,4-triazine(6)or 1-tosyl-3-methylthio-5-oxo-6-methyloxy-1,4,5,6-tetrahydro-1,2,4-triazine(7)was obtained respectively.The above reactions show anomalous properties of nucleophilic attack on 6-carbon in 1,2,4-triazine ring.
基金This project has been supported by Sichuan Youth Foundation (Grant No. 05ZQ026-054) the Natural Science Foundation of Sichuan Education Bureau (Grant No. 2005A102).
文摘Density functional theory B3LYP is employed to obtain the optimized geometries of the ground state and interaction energy for triazines and water complexes. The results show that the 1,2,3-triazine-water, 1,2,4-triazine-water and 1,3,5-triazine-water complex on the ground state have Cs, Cs and C1 symmetry, and strong hydrogen bonding interaction with ?17.83, ?17.38 and ?13.55 kJ/mol after basis set superposition error and zero-point vibration energy correction, respectively, and large red-shift for the symmetric H─O stretching vibration frequencies forming N···H─O hydrogen bond in the triazines complex. The first singlet (n, π*) vertical excitation energy of the monomer and the hydrogen bonding complexes between triazines and water is investigated by time-dependent density functional theory.
文摘As a continuation of the studies on the interference of metabolism of nucleic acids by 1,2,4-triazine derivatives, we have studied the preparation and chemical properties of a number of 1,2,4-triazines.
文摘FOR the purpose of finding novel antitumor and antivirus medicines and understanding themechanism of the metabolic process involved,several 6-azapurine derivatives were synthe-sized from 1,2,4-triazines.Mass spectrometry plays a key role in the structure
基金We thank the National Natural Science Foundation of China(Nos.21132005,21121004)the Ministry of Science and Technology of China(Nos.2011CB932501,2013CB834504)for financial support.
文摘A number of azacalix[2]pyrimidine[2]triazines were synthesized in moderate to good yields from both a step-wise fragment coupling approach and a one-pot reaction strategy starting from 4,6-diaminopyrimidines and cyanuric chloride.Nucleophilic aromatic substitution reaction of resulting dichloro-substituted azacalix[2]-pyrimidine[2]triazines with NH_(4)Cl led to the formation of NH_(2)-bearing azacalix[2]pyrimidine[2]triazine analogs.Azacalix[2]pyrimidine[2]triazines adopted symmetric 1,3-alternate conformations in solution while twisted 1,3-alternate conformations were observed in the solid state.In the presence of different additives during the growth of single crystals,azacalix[2]pyrimidine[2]triazines containing amino(-NH_(2))groups gave varied self-assembled structures due to the formation of different intermolecular hydrogen bond motifs.
基金Project supported by the National Natural Science Foundation of China (Nos. 20971041, 20803020, 20772027), the Key Project of Chinese Ministry of Education (No. 210146) and Scientific Research Fund of Hunan Provincial Education Department (Nos. 09B032, 09C385, 09K081).
文摘The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6(7H)-ones afforded novel dispiro[acenaphthylene-1,2’-pyrrolidine]-3',7″-[1,3]thiazolo[3,2-a][1,3,5]triazines in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis and X-ray crystallographic analysis. The results of experiment indicated that this 1,3-dipolar cycloaddition proceeded with high stereoselectivity and regioselectivity.
基金Ministry of Trade,Industry&Energy of Korea,Grant/Award Number:RS‐2022‐00155717National Research Foundation of Korea,Grant/Award Numbers:2020H1D3A1A04081472,2022M3J1A1054323。
文摘Carbon super-heterostructures with high nitrogen contents from the covalent hybrid precursors of covalent triazine frameworks(CTFs)and zeolitic imidazolic frameworks(ZIFs)are scarcely explored because of CTF's ordered structure and toxic superacid that dissolves or destabilizes the metal nodes.To solve this problem,herein,we report a straightforward two-step pathway for the covalent hybridization of disordered CTF(d–CTF)–ZIF composites via preincorporation of an imidazole(IM)linker into ordered CTFs,followed by the imidazole-site-specific covalent growth of ZIFs.Direct carbonization of these synthesized d–CTF−IM−ZIF hybrids results in unique hollow carbon super-heterostructures with ultrahigh nitrogen content(>18.6%),high specific surface area(1663m^(2)g^(−1)),and beneficial trace metal(Co/Zn NPs)contents for promoting the redox pseudocapacitance.As proof of concept,the obtained carbon super-heterostructure(Co–Zn–NC_(SNH)–800)is used as a positive electrode in an asymmetric supercapacitor,demonstrating a remarkable energy density of 61Wh kg^(−1)and extraordinary cyclic stability of 97%retention after 30,000 cycles at the cell level.Our presynthetic modifications of CTF and their covalent hybridization with ZIF crystals pave the way toward new design strategies for synthesizing functional porous carbon materials for promising energy applications.
基金the National Natural Science Foundation of China(Nos.21976069,21677062,21507155)。
文摘Porous polymer(pyrrolopyrrole)was successfully prepared via domino-ring-formation reaction.The chemical-physical properties of cyanided covalent triazine frameworks(CTF-CN)were characteriazed by fourier transform infrared spectra(FT-IR),scanning electron microscopy(SEM),nuclear magnetic resonance(NMR),specific surface area analyzer(BET)and thermogravimetric analysis(TGA),respectively.The experimental results of adsorption of chloranil(TCBQ)in aqueous solution indicated that CTF-CN exhibited distinctive adsorption capacity toward TCBQ owing to its large specific surface area.Specifically,the adsorption equilibrium of as-prepared polymer was executed within 5 h and the calculated adsorption capacity was 499.76 mg/g.Furthermore,the adsorption kinetics could be well defined with the linear pseudo-second-order model,which implies that the chemical interaction are relative important in the course of TCBQ removal.Finally,the current studies verify that CTF-CN has unique rigid and nano-porous framework structure,which can be employed for the treatment of a series of harmful aromatic substances.
文摘The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include organochlorines, triazines, organophosphates and pyrethroids. We conducted a study on the impact of these pesticide use, in particular organochlorines and triazines, on cotton farming soils. We chose the Plateaux region (southern Togo) as the study area because of its high cotton production. Analysis was carried out on crop soil samples at the 0 - 20 cm horizon. Several pesticide residues were found: simazine (0.051 to 0.103 μg/Kg soil);atrazine (0.149 to 0.197 μg/Kg soil);lindane (0.259 to 0.672 μg/Kg soil);β-endosulfan (1.37 to 5.727 μg/Kg soil);dieldrin (0.063 to 1.16 μg/Kg soil);endrin (0.512 μg/Kg soil), Heptachlor (0.489 to 1.243 μg/Kg soil);Heptachlor epoxide (0.928 to 1.633 μg/Kg soil);[2,4'DDT] (0.257 μg/Kg soil);[4,4'DDE] (0.262 μg/Kg soil). These results show pesticide contamination of cotton farming soils.
文摘Substituted 2-azoniaallene salts 1 are strong bifunctional electrophiles, undergo cyclization reactions furnish many series of heterocyclic compounds, where reacted with p-tolyl urea, phenyl thiourea and thiosemicarbazone derivatives to afford triazinium salts, and converted to corresponding free bases 3, 5, 7 under treatment with Na2CO3. While triazole derivatives 8 and 9 were obtained by the reaction 2-azoniaallene salts 1 with benzohydrazide and phenyl hydrazine, respectively. Benzoxazinium salts 10 and 11 were acquired when asymmetric 2-azoniaallene salt reacted in (1:1) ratio with p-cresol and 3-methyl-1-phenyl-5-pyrazolone, respectively. The reaction of 2-azoniaallene salt with malononitrile furnished the primidinium salt 12 which underwent neutralization with Na2CO3 followed by heterocyclization with hydrazine hydrate afforded the bicyclic compound 3-aminopyrazolo[3,4-d]pyrimidine 14, which is highly reactive for nucleophilic addition to phenyl isothiocyanate to furnish thiourea derivative 15. Moreover, 14 undergo condensation with aldehydes to give imine derivatives 16a,b. All free base compounds were screened for their antimicrobial activities.
文摘Adsorption of atrazine, prometryne and prometon was determined on six soils with different physical and chemical properties. The adsorption isotherms of three herbicides could well fit Freundlich equation. On all of six soils, adsorption of herbicides increased in the order: atrazine ≈prometon<prometryne. This order is quite the same to the calculation result of by means of excess thermodynamic properties of triazine. The Freundlich adsorption constants, K f, showed to have good correlation with organic matter(OM%) of soils for each of these herbicides, suggesting that OM is the main factor, which dominates in the adsorption process of these triazine herbicides.
文摘A new method for the synthesis of 4,4′,6,6′-tetra(azido)azo-1,3,5-triazine (TAAT) is described. The key intermediate 4,4′,6,6′-tetra(azido)hydrazo-1,3,5-triazine (TAHT) was synthesized by nucleophilic substitution in the case of sodium azide as nucleophile. N-Bromosuccinide (NBS) was used as oxidant to oxidize TAHT by a tractable operation under mild reaction condition. The target compound TAAT was obtained with a facile process and high overall yield of 81%. The structures of TAAT and its intermediates were identified by spectroscopic methods.
基金the support from the National Key Research and Development Program(No.2018YFB1107500)the National Natural Science Foundation of China(No.51503024)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.DUT17RC(3)003,DUT18RC(4)033)the National Natural Science Foundation of the Joint Fund Key Projects(No.U1663226)。
文摘2D MXenes are attractive for energy storage applications because of their high electronic conductivity.However,it is still highly challenging for improving the sluggish sodium(Na)-ion transport kinetics within the MXenes interlayers.Herein,a novel nitrogen-doped Ti3C2Tx MXene was synthesized by introducing the in situ polymeric sodium dicyanamide(Na-dca)to tune the complex terminations and then utilized as intercalation-type pseudocapacitive anode of Na-ion capacitors(NICs).The Na-dca can intercalate into the interlayers of Ti3C2 Tx nanosheets and simultaneously form sodium tricyanomelaminate(Na3TCM)by the catalyst-free trimerization.The as-prepared Ti3C2Tx/Na3TCM exhibits a high N-doping of 5.6 at.%in the form of strong Ti-N bonding and stabilized triazine ring structure.Consequently,coupling Ti3C2Tx/Na3 TCM anode with different mass of activated carbon cathodes,the asymmetric MXene//carbon NICs are assembled.It is able to deliver high energy density(97.6 Wh kg-1),high power output(16.5 kW kg-1),and excellent cycling stability(≈82.6%capacitance retention after 8000 cycles).
文摘Potential of nanoscale triazine based dendritic macromolecules G1,G2 and G3 as solubility enhancers of drug was investigated.Effect of pH,concentration and generation of synthesized dendritic macromolecules on solubility of ketoprofen was studied.G3 dendrimer was further exploited as carrier for sustained release.Ketoprofen was encapsulated by inclusion complex method and also characterized by Flourier Transform Infrared spectroscopy.Sustained release study of ketoprofen from ketoprofen loaded dendrimer was carried out and compared with free ketoprofen.Hemolytic potential and Cytotoxicity assay using A-549 lung cancer cell lines revealed that synthesized triazine based dendritic macromolecules having more potential that commercially available PAMAM dendrimer.
基金sponsored by the Natural Science Foundation of Hebei (Nos.B2006000413,B2008000210).
文摘A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography (MEKC) was developed. Various parameters affecting sample enrichment and separation efficiency were systematically studied. Compared with the conventional MEKC method, up to 60-200-fold improvement in concentration sensitivity was achieved in terms of peak height by using this sweeping injection technique. The compound strychnine was used as the internal standard for the improvement of the experimental reproducibility. The limits of detection (S/ N = 3:1) for atrazine, simazine and prometryn were 9, 10 and 0.5 ng mL-1, respectively. This method has been successfully applied to the analysis of atrazine, simazine and prometryn in lake, steam and ground water.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(grant number:2015042434)the support by the Korea Research Fellowship Program(grant number:2017H1D3A1A02013620)
文摘Highly porous nitrogen-doped carbon materials were synthesized by the carbonization of a low-cost porous covalent triazine polymer, PCTP-3, which had been synthesized by the AlClcatalyzed FriedelCrafts reaction of readily available monomers. The nature of the bond and structure of the resulting materials were confirmed using various spectroscopic methods, and the effects of KOH activation on the textural properties of the porous carbon materials were also examined. The KOH-activated porous carbon(aPCTP-3c) materials possessed a high surface area of 2271 mgand large micro/total pore volumes of 0.87/0.95 cmg, respectively, with narrower micropore size distributions than the porous carbon prepared without activation(PCTP-3c). The aPCTP-3c exhibited the best COuptakes of 284.5 and 162.3 mg gand CHuptakes of 39.6 and 25.9 mg gat 273 and 298 K/1 bar, respectively, which are comparable to the performance of some benchmark carbon materials under the same conditions. The prepared materials exhibited high CO/Nselectivity and could be regenerated easily.
基金National Natural Science Foundation of China(Grant nos.21671172,21625604,21706229,21776251)Zhejiang Provincial Natural Science Foundation of China(Grant no.LR19B010001)open fund of State Key Laboratory of Structural Chemistry(No.20170036)。
文摘Research on water-splitting electrocatalysts is crucial to establishing a solution to the energy crisis.Herein,we report a facile bottom-up strategy for the preparation of high performance supported electrocatalysts for overall water-splitting reaction via a rationally designed defect covalent triazine frameworks(CTFs)support.Specifically,defect CTFs are obtained via binary-precursor polymerization,followed by loading Ru nanoparticles(Ru/D-CTFs-900)with high HER performance at a current density of 10 mA cm-2.The overpotential is only 17 mV.Calcination of the resultant Ru–RuO2/D-CTFs-300 in air,produces excellent OER performance with 190 mV overpotential(at 10 mA cm-2).Furthermore,overall water splitting measurements reveal the potential of 1.47 V,which is better than the majority of the reported Ru-based catalysts.Moreover,density functional theory calculation results show that excellent electrocatalytic properties are attributed to the synergistic effect of Ru nanoparticles and carbon support.
文摘Four Schiff bases, from pyruvic acid (1) with amines containing N and S donor atoms, thiocarbohydrazide (2, 61%), 2-methyl-3-thiosemicarbazide (3, 26%), S-benzyldithiocarbazate (4, 51%) and S-n-octyldithiocarbazate (5, 63%) have been successfully synthesized. The conventional method was used and a series of novel linear and cyclic Schiff bases were obtained with or without catalyst. All the Schiff bases were fully characterized by CHN elemental analysis, FT-IR, 1H & 13C NMR, EI-MS and two of the Schiff bases were further characterized by X-ray crystallographic structure analysis. Compound 2 crystallizes in the triclinic space group P-1 and unit cell dimensions are: a = 4.1777(8), b = 5.9538(11), c = 13.458(3) &ARING;, α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0439. Compound 3 crystallizes in the orthorhombic space group P n a 2(1) and unit cell dimensions are: a = 5.5992(2), b = 11.3962(5), c = 10.6473(5), α = 92.759(6), β = 90.813(6), γ = 100.040(6)°, R1 = 0.0285. Compounds 2 and 3 were obtained as cyclic Schiff bases which are triazine derivatives.
文摘Simazine and propazine are selective triazine herbicides currently in use to control broad-leaved weeds and annual grasses around the world. Bisphenol A (BPA) is an industrial chemical used in the production of polycarbonate plastics often found in consumer goods, such as plastic containers, baby bottles etc. These synthetic compounds are known to increase the risk of cancer, cause adverse reproductive effect in reptiles, mammals, birds, humans, and lead to other health problems. They have become some of the principal agents of contamination in water bodies around the world through herbicide runoff, industrial waste and leaching. Some triazines such as atrazine are banned in most European countries for over ten years due to their adverse reproductive effect in mammals, birds and humans;however propazine and simazine are still in use around the world. The removal of these compounds from contaminated water is an exigent challenge. In this study, we investigated their affinity for the surface of nanoparticles (NPS) and standard metallic oxides in an effort to exploit the unique potential applications of NPS for water purification systems. We studied the adsorption of the two triazines and BPA on the surface of NPS of iron (III) oxide, NPS of carbon, bulk iron (III) oxide and aluminum oxide at pH 6 and pH 8 using UV-Visible spectroscopy. Result indicates that these compounds have different affinity towards the surface of metallic oxides and carbon at various pHs. In general, there is relatively high adsorption of some of these compounds on the surface of NPS compared to bulk particles. NPS of carbon have shown the highest affinity for all the three compounds. The lower pH was found to be favorable for all of the compounds except for BPA. BPA have shown high adsorption at pH 8 than at pH 6.
基金sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘The title compound 4-oxo-1,2,4-triazino[4,5-a]benzimidazole(C9H6N4O,Mr = 186.18) has been synthesized and structurally characterized by IR,NMR and single-crystal X-ray diffraction. The crystal belongs to monoclinic,space group P21/c,with a = 9.1530(18) ,b = 7.2260(14),c = 12.604(3) ,β = 106.92(3) ,V = 797.5(3)A^3,Z = 4,Dc = 1.551 g/cm^3,λ(MoKa) = 0.71073,F(000) = 384,μ(MoKa) = 0.109 mm^-1,the final R = 0.0632 and wR = 0.1095. A total of 1444 unique reflections were collected,of which 767 with I 〉 2σ(I) were observed. The structure of the title compound is planar. In packing,the molecules are intersected to each other to form chains along three dimensions,together by intermolecular N-H…O and C-H…N hydrogen bonds. The whole structure is further stabilized by π…π interaction between two adjacent tricyclic ring systems,with the centroid-to-centroid distance of 3.369(4) A.