Imidazole linker‐induced covalent triazine framework-ZIF hybrids for confined hollow carbon super‐heterostructures toward a long‐life supercapacitor

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.

Cyanided Covalent Triazine Frameworks with Enhanced Adsorption Capability Toward Chloranil

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.

Adsorption and correlation with their thermodynamic properties of triazine herbicides on soils

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.

A new efficient route for the synthesis of 4,4′,6,6′-tetra-(azido)azo-1,3,5-triazine

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.

Determination of triazine herbicide residues in water samples by on-line sweeping concentration in micellar electrokinetic chromatography

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.

Facile synthesis of microporous carbonaceous materials derived from a covalent triazine polymer for CO2 capture

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.

Synthesis and Photo-acid Generation of a Novel Bis(trichloromethyl)-1,3,5-triazine

A new environmentally friendly photo-acid generator（PAG）, 1-{4＇-[4,6-bis（trichloromethyl）-1,3,5-triazin- 2-yl] [ 1, 1＇-biphenyl]-4-yl}-O-acetyloxime ethanone（TZ4） consisting of both an oxime ester group and a triazine group was designed and synthesized. From the measurements of absorption, fluorescence and the photo-acid generation, it was found that the novel PAG has an excellent radical-generating efficiency. And the other three bis-（trichloromethyl） triazine derivatives 2-[2-（4-methoxyphenyl）ethenyl]-4,6-bis（trichloromethyl）-l,3,5-triazine（TZ1）, 2-[2-（3,4-dimethoxyphenyl）ethenyl]-4,6-bis（trichloromethyl）-1,3,5-triazine（TZ2） and 2-（1,3-benzodioxol-5-yl）-4,6-bis（trichloromethyl）-1,3,5-triazine（TZ3） were synthesized and studied in this work. In the acid measurement, the acid-forming performance of S-triazinyl derivatives was evaluated by the method ascertained in our laboratory. The results indicate that the novel triazine has the better acid-forming performance that subsequently catalyzes the deblocking of a protecting group in copolymers.

Syntheses and Crystal Structures of 1,5-Disubstituted 1,3,5-Hexahydro-triazine-2-(N-nitro)imines

The title compounds,C9H13ClN6O2S 1 and C15H17ClN6O2S 2,were synthesized and structurally characterized by elemental analysis,IR,1H NMR spectra and single-crystal X-ray diffraction.Compound 1 is in the monoclinic system,space group P21/c with a=13.7711（5）,b=10.3883（4）,c=9.7623（2）,V=1344.47（8）3,Dc=1.506 g/cm3,C9H13ClN6O2S,Mr=304.76,F（000）=632,μ=0.448 mm-1,Z=4,S=1.084,R=0.0497 and wR=0.1328 for 2640 unique reflections（Rint=0.0787） with 2089 observed ones（I2σ（I））.Compound 2 belongs to the monoclinic system,space group P21/n with a=8.3828（5）,b=14.5285（7）,c=14.2456（4）,V=1729.74（14）3,Dc=1.462 g/cm3,C15H17ClN6O2S,Mr=380.86,F（000）=792,μ=0.364 mm-1,Z=4,S=1.057,R=0.0598 and wR=0.1582 for 3384 unique reflections（Rint=0.0469） with 2833 observed ones（I2σ（I））.Compounds 1 and 2 are homologues and stabilized by intermolecular and intramolecular hydrogen bonds.Moreover,compound 2 containing C（2）–H（2）…π（thiazole） interaction is more stable than 1.

Clean Production for Chrome Free Leather by Using a Novel Triazine Compound

Based on a novel triazine compound,the properties of tanned leather and commercial feasibility in pilot scale have been investigated.Then this novel approach tanning was compared with conventional chrome tanning:in the condition of less-salt pickling and chrome free,the physicochemical properties including thermal stability and mechanical strength were analyzed.Meanwhile,the surface roughness and fiber dispersion were evaluated as well.The results show that the thermal stability and mechanical strength of the triazine compound tanned leather are similar to conventional chrome tanned leather,the fiber bundle is well-dispersed and much evener than that of chrome treating.The optimized tanning approach has obvious reduction in environmental impact and leads an excellent biodegradability of tanning liquor.In industrial application,the cost of materials and water treatment are reduced effectively.The production of chrome free leather can encourage the sustainable development of leather industry and protects ecological environment in some extent.

Styrene Epoxidation in Aqueous over Triazine-Based Microporous Polymeric Network as a Metal-Free Catalyst

Tirazine based microporous polymeric (TMP) network was found to be an efficient metal-free catalyst for the epoxidation of styrene. The reactions were performed in water as an environmentally benign medium using H2O2 as a green oxidant at ambient temperature. The reaction afforded higher yield with 90% conversion of styrene and 98% selectivity to styrene oxide in 6 h. The triazine based microporous polymeric network can be readily recovered and reused up to 4 cycles without significant loss in catalytic activity and selectivity.

CHEMISTRY OF 1,2,4—TRIAZINES XIX THE ANOMALOUS SUBSTITUTED BENZENE SULFONATION AND PROPERTIES OF NUCLEOPHILIC ATTACK ON 6-CARBON OF 3-METHYLTHIO-5-HYDROXY-1,2,4-TRIAZINE

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.

Covalent Triazine Framework Nanosheets:Synthesis and Energy Conversion and Storage

Covalent triazine framework nanosheets (CTF NSs),an emerging class of two-dimensional nanomaterials,have received great attention due to their abundant active sites,permanent porosity,molecular structural diversity,superior chemical/thermal stability,and short charge diffusion path,enabling technological breakthroughs in a myriad of applications. The forefront developments and applications of CTF NSs as photocatalysts and electrochemical electrodes have conferred superior performance and made great impact in the field of energy and advanced catalysis. This forward-looking review aims to summarize the research trends,synthesis,properties of CTF NSs and their CTF counterpart,and highlight their progress in applications with respect to energy storage and conversion devices. Finally,the current challenges and future perspectives for CTF NSs are also presented.

Crystalline covalent triazine frameworks manipulated by aliphatic amine modulator

Crystallization is an unsolved challenge in the chemistry of covalent triazine frameworks(CTFs) due to the poorly controlled simultaneous polymerization and crystallization processes. Herein, the synthesis of crystalline CTFs via the introduction of aliphatic amine as a dynamic modulator is reported. By optimizing the amount of aliphatic amine, the crystallization process can be controlled in an open system, resulting in the synthesis of crystalline CTFs. These crystalline CTFs exhibit much better photocatalytic hydrogen evolution performance, with highly ordered CTF-1-C3 demonstrating superior performance(10 mmol g^(-1)h^(-1)) compared with most reported CTF-1. This approach also allows for the preparation of various crystalline CTFs.

Nickel-Catalyzed Cross-Electrophile Coupling of Triazine Esters with Aryl Bromides

Cross-electrophile coupling of triazine esters with aryl bromides could be facilely accomplished by employing nickel as catalyst,magnesium as metal mediator,and lithium chloride as additive.The reactions proceeded efficiently in THF at room temperature through C—O bond activation to afford an array of structurally different diaryl ketones in moderate to good yields with wide functional group tolerance.Control experiments showed that nickel,magnesium,lithium chloride,and THF are all indispensable for the good performance of the coupling reaction.Preliminary mechanistic exploration indicated that in situ formed arylmagnesium reagent by the insertion of magnesium into aryl bromide might serve as the key intermediate of the cross-coupling.The method which avoids the utilization of moisture-labile and relatively difficult-to-obtain organometallics is step-economical,cost-efficient,and operationally simple,potentially serving as an attractive alternative to documented methods.

Insight into the structural transformation of tetraphenylethylene acids at liquid–solid interface induced by linear aminofunctionalized triazine derivatives and annealing treatment

The interaction between organic photoelectric molecules leads to the formation of a certain aggregation structure,which plays a pivotal role in the charge transport at the intermolecular interface.In view of this,we investigated the mechanism and law of intermolecular interaction by detecting the self-assembled behaviors between organic photoelectric molecules at the interface by scanning tunneling microscopy(STM).In this work,the structural transformations of tetraphenylethylene acids(H_(4)ETTCs)on graphite surface induced by temperature and triazine derivatives(zcy-19,zcy-27,and zcy-38 molecules)were studied by STM technology and density functional theory(DFT)calculations.At room temperature,zcy-19 and H_(4)ETTC molecules formed a small range of ordered co-assembled nanostructure,while for zcy-27 or zcy-38 molecules,no co-assembled nanostructures were observed and only their own self-assembled structures existed on graphite surface,individually.In the thermal annealing trials,the original co-assembled H_(4)ETTC/zcy-19 structure disappeared,and only zcy-19 and H_(4)ETTC self-assembled in separate domains.Nevertheless,new well-ordered H_(4)ETTC/zcy-27 or H_(4)ETTC/zcy-38 co-assembled structures appeared at different annealing temperatures,respectively.Combined with DFT calculations,we further analyzed the mechanism of such structural transformations by triazine derivatives and temperature.Results reveal that triazine derivatives could interact with H_(4)ETTC by N–H···O and O–H···N hydrogen bondings,and whether temperature or zcy series compounds could achieve successful regulation of H_(4)ETTC assembly behavior is closely associated with the conjugated skeleton length of zcy series compounds.

Floret-like Fe-N_(x)nanoparticle-embedded porous carbon superstructures from a Fe-covalent triazine polymer boosting oxygen electroreduction

Fe–N_(x)nanoparticles-embedded porous carbons with a desirable superstructure have attracted immense attention as promising catalysts for electrochemical oxygen reduction reaction.Herein,we employed Fe-coordinated covalent triazine polymer for the fabrication of Fe–N_(x)nanoparticle-embedded porous carbon nanoflorets(Fe/N@CNFs)employing a hypersaline-confinement-conversion strategy.Presence of tailored N types within the covalent triazine polymer interwork in high proportions contributes to the generation of Fe/N coordination and subsequent Fe–N_(x)nanoparticles.Owing to the utilization of NaCl crystals,the resultant Fe/N@CNF-800 which was generated by pyrolysis at 800℃showed nanoflower structure and large specific surface area,which remarkably suppressed the agglomeration of high catalytic active sites.As expect,the Fe/N@CNF-800 exhibited unexpected oxygen reduction reaction catalytic performance with an ultrahigh half-wave potential(0.89 V vs.reversible hydrogen electrode),a dominant 4e–transfer approach and great cycle stability(>92%after 100000 s).As a demonstration,the Fe/N-PCNF-800-assembled zinc–air battery delivered a high open circuit voltage of 1.51 V,a maximum peak power density of 164 mW·cm^(-2),as well as eminent rate performance,surpassing those of commercial Pt/C.This contribution offers a valuable avenue to exploit efficient metal nanoparticles-based carbon catalysts towards energy-related electrocatalytic reactions and beyond.

In-situ doping strategy for improving the photocatalytic hydrogen evolution performance of covalent triazine frameworks

A highly conjugated network of covalent triazine frameworks(CTFs)on the one hand promotes light-harvesting,but on the other hand,also results in high carrier recombination which eventually limits their photocatalytic hydrogen evolution reaction(HER)rates.Thus,strategies to favorably tune the electronic configuration of CTFs for efficient photocatalytic HERs need to be developed,but still remain challenging.Herein,a simple in-situ defect strategy involving element doping is developed for the first time to introduce a heteroatom including S and Se into CTF-1 via the condensation of aldehydes with the mixture of the terephthalimidamide and the S-or Se-substituted terephthalimidamide under mild conditions.The doping content(X)is varied,resulting in a series of S-and Se-doped CTFs,named CTFS-1-X and CTFSe-1-X,respectively.Interestingly,for the S-doped CTFs,CTFS-1-10 shows the most excellent HER rate(4,992.3μmol g^(-1)h^(-1))from water splitting,while for the Se-doped ones,CTFSe-1-10 exhibits a photocatalytic HER rate of 5,792.8μmol g^(-1)h^(-1),both of which far surpass undoped CTFs(693.3μmol g^(-1)h^(-1)).In-depth studies indicate that the introduction of S or Se atoms into CTFs could extend the light absorption and promote photo-generated electron-hole pairs migration.Meanwhile,S-or Se-doping could create heterogeneous electronic configuration in CTFs,which can help to suppress carrier recombination.

0D/3D direct Z-scheme heterojunctions hybridizing by MoS2 quantum dots and honeycomb conjugated triazine polymers (CTPs) for enhanced photocatalytic performance

Herein,a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots(MSQDs)and 3D honeycomb-like conjugated triazine polymers(CTP)(namely,CTP-MSQD).The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property,while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators.The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI)reduction and H2 evolution,featured a rate of 0.069 min^(-1) and 1070μmol/(hr•g),respectively,which were 8 times than those of pure 3D-CTP(0.009 min^(−1) and 129μmol/(hr•g)).We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion.

Hydrolysis of Polyphenyl-1,2,4-triazine and Polyphenyl-1,3,5-triazine in High Temperature Water

The hydrolysis of polyphenyl 1,2,4 triazine (As PPT) and polyphenyl 1,3,5 triazine (S PPT) in water at 250℃/ 3.97 MPa under nitrogen atmosphere has been investigated experimentally and theoretically. The hydrolysis reactions were monitored by Fourier transform infrared (FT IR) and ultra violet visible (UV Vis) spectra. The results show that S PPT is remarkably stable whereas As PPT is easily hydrolyzed in water at 250℃. The identifications using FT IR, high performance liquid chromatography (HPLC), nuclear magnetic resonance ( 1H NMR) and mass spectrography (MS) confirm that terephthalic acid is the major hydrolysate of As PPT. Two model compounds, 2,5,6 triphenyltriazine and 2,4,6 triphenyltriazine, were designed to simulate the local electronic structures of As PPT and S PPT, respectively. The electronic structures were given by ab initio calculations at the RHF/4 31G level. The calculational results indicate that the triazine rings are the hydrolytically active parts and the 1,2,4 triazine ring is easier to hydrolyze in comparison with the 1,3,5 triazine ring under the same condition.

Covalent Triazine Frameworks-derived N,P Dual-doped Porous Carbons for Highly Efficient Electrochemical Reduction of CO_(2)

Electroreduction of CO_(2)into chemicals is of great importance in the global carbon balance.Although noble-metal based catalysts and single-atom catalysts(SACs)are known to be active for CO_(2)electroreduction reaction(CO_(2)RR),the high cost of noble-metal and the lack of effective synthesis approaches to prepare SACs have tremendously hindered the application.Non-metal doped carbon materials have attracted great interest because of their reasonable cost,chemical stability and excellent electrical conductivity.Nevertheless,the design and fabrication of highly efficient non-metal doped carbon electrocatalysts for CO_(2)RR to meet industry demands still remains a big challenge.Herein,triphenylphosphine@covalent triazine frameworks(CTFs)composites were employed as precursors to fabricate N,P dual-doped porous carbon catalysts PCTF-X-Y(X represents the carbonization temperature,and Y represents the mass ratio of CTF to triphenylphosphine)for CO_(2)RR.Due to the high specific surface areas and synergistic effect between N and P,the obtained PCTF-1000-5 exhibited high selectivity for CO production up to 84.3%at–0.7 V versus the reversible hydrogen electrode(vs.RHE)and long-term durability over 16 h,which are better than the reported N,P dual-doped carbon catalysts in aqueous media.This work provides a new way to design and fabricate non-metal catalysts for electrocatalysis.