Isothiocyanates(ITCs)are an important class of organic compounds characterized by the functional group R-N=C=S.These functional groups are widely found in multiple natural products and pharmaceutical important drugs.M...Isothiocyanates(ITCs)are an important class of organic compounds characterized by the functional group R-N=C=S.These functional groups are widely found in multiple natural products and pharmaceutical important drugs.Moreover,due to their high and versatile reactivity,they are widely used as an intermediate in organic synthesis.Keeping in view ITCs importance,this review summarizes their synthesis from nitrogen rich raw materials like amines,isocyanides,azides and some other compounds like oximes.Besides their synthesis,their application in organic compound synthesis as an intermediate will also be covered.Future research will likely focus on optimizing the synthesis of multifunctional isothiocyanates,understanding their complex biological mechanisms,exploring new applications,and highlighting the continued importance of isothiocyanates in modern chemistry and biotechnology.展开更多
Currently, industrial production of isocyanates, or diisocyanates in particular, has been exclusively based on phosgene processes. Phosgene is extremely toxic and large amounts of corrosive HC1 are produced as a side ...Currently, industrial production of isocyanates, or diisocyanates in particular, has been exclusively based on phosgene processes. Phosgene is extremely toxic and large amounts of corrosive HC1 are produced as a side product. In the view of environment protection and society safety, development of non-phosgene processes for isocyanates production will be highly desired, and this should be one of the most important missions for green chemistry and catalysis. In this review, efforts for development of non-phosgene method for syntheses of isocyanates, i.e., catalytic syntheses of N-substituted carbamates from nitro- or amino-compounds with CO, dimethyl carbonate （DMC）, urea and even CO2 etc. as carbonyl sources, then thermal cracking of N-substituted carbamates to afford corresponding i socyanates, are summarized, and a brief prospect for non-phosgene syntheses of isocyanates is also addressed.展开更多
The effects of isocyanate(IA)incorporation on the toughness and volume stability of AAFS were systematically investigated.Various IA dosages were introduced into AAFS,and their influence on mechanical properties,micro...The effects of isocyanate(IA)incorporation on the toughness and volume stability of AAFS were systematically investigated.Various IA dosages were introduced into AAFS,and their influence on mechanical properties,microstructure,and shrinkage behavior was evaluated.The experimental results indicate that,with the incorporation of 5%IA,the 28-day compressive strength reaches 48.6 MPa,the 56-day drying shrinkage decreases by 35.91%,and minimal cracking is observed in the ring test.Microstructural analyses using SEM,XRD,and FTIR reveal that IA reacts with water to form urethane and biuret,which crosslinks into a durable network structure.This network fills pores,reducing internal stresses and improving both toughness and volume stability.These findings offer new insights into optimizing alkali-activated materials for construction applications and provide a potential pathway for the development of more durable and stable geopolymers.展开更多
Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reage...Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reagents that can replace cyanide. This paper intro-duces a method for synthesizing a gold leaching reagent. Sodium cyanate is used as the main raw material, with sodium hydroxide and so-dium ferrocyanide used as additives. The gold leaching reagent can be obtained under the conditions of a mass ratio of sodium cyanate,sodium hydroxide, and sodium ferrocyanide of 15:3:1, synthesis temperature of 600℃, and synthesis time of 1 h. This reagent has a goodrecovery effect on gold concentrate and gold-containing electronic waste. The gold leaching rate of roasted desulfurized gold concentratecan reach 87.56%. For the extraction experiments of three types of gold-containing electronic waste, the gold leaching rate can reach over90% after 2 h. Furthermore, the reagent exhibits good selectivity towards gold. Component analysis indicates that the effective compon-ent in the reagent could be sodium isocyanate.展开更多
The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes/triisobutyl aluminum (Ln(H<sub>2</sub>salen)<sub>2</sub>Cl<sub>3</sub>·2C<sub>2&l...The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes/triisobutyl aluminum (Ln(H<sub>2</sub>salen)<sub>2</sub>Cl<sub>3</sub>·2C<sub>2</sub>H<sub>7</sub>OH/Al(i-Bu)<sub>3</sub>) at room temperature was investigated. The influences of ligand structure, catalyst composition, polymerization temperature, polymerization time, the concentration of catalyst and monomer, and the polymerization solvent on the polymerization of isocyanates were studied. It was found that under the polymerization conditions, examined La(H<sub>2</sub>salen<sub>A</sub>)<sub>2</sub>Cl<sub>3</sub>·2C<sub>2</sub>-H<sub>7</sub>OH/Al(i-Bu)<sub>3</sub> (H<sub>2</sub>salen<sub>A</sub>= N,N′-disalicylideneethylene diamine) is a fairly high efficient catalyst for the polymerization of n-hexyl isocyanate (n-HexNCO) to prepare high molecular weight poly(n-hexyl isocyanate) (PHNCO) with narrower molecular weight distribution at room temperature. PHNCO could be prepared with yield of 74.0%, number-average molecular weight (M <sub>n</sub>) of 40.20×10<sup>4</sup> and MWD of 1.79 under the following optimum conditions: [Al]/[La] = 30 (molar ratio), [n-HexNCO]/[La] = 100 (molar ratio), [n-HexNCO] = 3.43 mol/L polymerization at 20°C for 12 h in toluene. In the same polymerization conditions, poly (n-octyl isocyanate) (PONCO) with yield of 67.3%, and poly(n-butyl isocyanate) (PBNCO) with yield of 45.5%, could be prepared respectively. The kinetics of the polymerization of n-HexNCO was also investigated and found to be first-order with respect to both monomer and catalyst concentrations.展开更多
The orientation of the addition of 5-amino-3-benzylthio-1,2,4-triazole and its analogues (pyrazole) (1) with the aryl isocyanate can be directed by controlling the reaction temperature and one of the product, 5-amino-...The orientation of the addition of 5-amino-3-benzylthio-1,2,4-triazole and its analogues (pyrazole) (1) with the aryl isocyanate can be directed by controlling the reaction temperature and one of the product, 5-amino-1-arylaminocarbonyl-3-benzylthio-1,2,4-triazole (pyrazole) (2), can rearrange at 170C to another product, 5-arylureylene-3-benzylthio-1,2,4-triazole (pyrazole) (3). A plausible mechanism explanation for this rearrangement reaction was presented. It was suggested that the rearrangement reaction could be referred to the thermodynamics transposition leading to the predominant 5-arylureylene-3-benzylthio-1,2,4-triazole energy preferentially.展开更多
The reaction of 3-substituted-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides with aryl isocyanate under different equivalents of strong base NaH was studied. Seventeen of new derivatives were obtained whose structures we...The reaction of 3-substituted-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides with aryl isocyanate under different equivalents of strong base NaH was studied. Seventeen of new derivatives were obtained whose structures were characterized by H-1 NMR, IR, MS, elementary analysis and FeCl3 test.展开更多
Zeolite imidazole skeleton(ZIF-8)is a promising option for self-cleaning of building exterior walls due to its large specific surface area,high antibacterial activity and low biotoxicity.However,it suffers from low an...Zeolite imidazole skeleton(ZIF-8)is a promising option for self-cleaning of building exterior walls due to its large specific surface area,high antibacterial activity and low biotoxicity.However,it suffers from low antibacterial efficiency and yield under visible light irradiation.To address the issues,we developed the photocatalytic materials T-ZIF-8-TDI(thermally treated-ZIF-8-toluene 2,4-diisocyanate)by modifying ZIF-8 with thermal oxygen sensitization and chemical bonding.The results show that the yield of T-ZIF-8-TDI photocatalytic antibacterial agent is increased to 11.5 times of that of T-ZIF-8,while maintaining the crystal structure of T-ZIF-8 and thermal stability up to 60℃.Furthermore,T-ZIF-8-TDI exhibits extended optical response range to the nearinfrared region,significantly narrowed band gap,improved photogenerated elec tron-hole separation efficiency,reduced recombination rate,and excellent photocatalytic performance.When the concentration of antibacterial agent is 600 mg·L^(-1),the antibacterial rate of Escherichia coli(E.coli)reaches 99.99%irradiated by visible light for30 min,and when the concentration of antibacterial agent is 200 mg·L^(-1),the antibacterial rate of Staphylococcus aureus(S.aureus)reaches 99.99%irradiated by visible light for 25 min.We also analyzed the reasons in detail from the aspects of bacterial species and antibacterial mechanism,and proposed the antibacterial mechanism of·O_(2)^(-)and h^(+)as the main active species.These findings suggest that T-ZIF-8-TDI photocatalytic antibacterial agent has potential for use in self-cleaning of building exterior walls.展开更多
With the urgent shortage of forest resource in China, using agro-residues as raw materials of composite become increasingly important. Agro-residue is the most potential fiber resource, which is helpful to sustainable...With the urgent shortage of forest resource in China, using agro-residues as raw materials of composite become increasingly important. Agro-residue is the most potential fiber resource, which is helpful to sustainable development of composite industries in China. Based on a great deal of researches, this paper summarized and discussed some problems in using agro-residues as raw materials of composites, including raw material preparation, hot-pressing, bonding technology, preventing composite from going moldy. It is proposed that to manufacture the composite of rice straws or wheat straws, the isocayante resin is a suitable adhesive, and the appropriate technologies, bonding, and treatment measures are also needed.展开更多
The carbodiimide 2,obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates,reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4（3H）-ones 4 and 5.The formation ...The carbodiimide 2,obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates,reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4（3H）-ones 4 and 5.The formation mechanism of the title compounds has been investigated.展开更多
Oil spills and oil/water wastewater are among the great concerns regarding oil pollution.Existing technologies face many limitations and in some cases are responsible for causing secondary pollution,therefore there is...Oil spills and oil/water wastewater are among the great concerns regarding oil pollution.Existing technologies face many limitations and in some cases are responsible for causing secondary pollution,therefore there is as seek for environmental friendly solutions.Biomass,from which celluloses are highlighted,are being employed for oil/water separation or oil absorbents membranes.Usually,these membranes are obtained by freeze drying of CNF(cellulose nano-fibrils)suspensions followed by chemical modification for hydrophobization,which involves expensive process as chemical vapor deposition and expensive reactants as sylanes,turning these processes hardly scalable.Here,we produced a natural porous structure paper from eucalyptus pulp fibers modified by a dipping and heating process in a blocked diisocyanate solution.After the surface treatment,contact angle with water reached 144°and water absorption reduced seven times,keeping the good oil absorbance.The chemical modification process is simple to be performed and use a very low quantity of reactant estimated to be less than 0.1 wt%based on cellulose.The good mechanical properties of the material allows its use in non usual conditions which can be of great importance depending on the environmental conditions.展开更多
In search of new anticancer agents, a series of novel 1-benzhydryl-4-(substituted phenylcarboxamide / carbothioamide)-1,4-diazepane derivatives were designed, synthesized and characterized using 1H NMR, LCMS and eleme...In search of new anticancer agents, a series of novel 1-benzhydryl-4-(substituted phenylcarboxamide / carbothioamide)-1,4-diazepane derivatives were designed, synthesized and characterized using 1H NMR, LCMS and elemental analysis. These molecules were evaluated for their anti-cancer activity by trypan blue exclusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on B-cell leukemic cell line, Reh. Carboxamide moiety containing derivatives showed good activity compared to the corresponding carbothioamide derivatives. In particular, 4-benzhydryl-N-(3-chlorophenyl)-1,4-diazepane-1-carboxamide showed good activity with IC50 value of 18 μM.展开更多
The photodissociation dynamics of isocyanic acid （HNCO） has been studied by the time- sliced velocity map ion imaging technique at 193 nm. The NH（a1△） products were measured via （2＋1） resonance enhanced multip...The photodissociation dynamics of isocyanic acid （HNCO） has been studied by the time- sliced velocity map ion imaging technique at 193 nm. The NH（a1△） products were measured via （2＋1） resonance enhanced multiphoton ionization. Images have been accumulated for the NH（a1△） rotational states in the ground and vibrational excited state （v=0 and 1）. The center-of-mass translational energy distribution derived from the NH（a1△） images implies that the CO vibrational distributions are inverted for most of the measured 1NH（v｜j） internal states. The anisotropic product angular distribution observed indicates a rapid dissociation process for the N-C bond cleavage. A bimodal rotational state distribution of CO（v） has been observed, this result implies that isocyanic acid dissociates in the S1 state in two different pathways.展开更多
The reaction of isocyanates with aliphatic and aromatic amines in the 1-n-butyl-3- methylimidazolium tetrafluoroborate (bmimBF4) ionic liquid in good to excellent yields is described. Due to its insolubility, the des...The reaction of isocyanates with aliphatic and aromatic amines in the 1-n-butyl-3- methylimidazolium tetrafluoroborate (bmimBF4) ionic liquid in good to excellent yields is described. Due to its insolubility, the desired urea solids could be recovered by simple filtration from the ionic liquid after reaction.展开更多
Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes...Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes) from solutions has been studied. As expected, the scavenging efficiency is directly proportional to the number of nucleophic nitrogens present on the resin. The results have been compared with the performance of the popular scavenger resin, namely, tris(2-aminoethyl)amine resin, to conclude that the low-cost polyamine resins now prepared can be conveniently used as effectively as the expensive commercial product.展开更多
Fire effluents, in most cases, have an adverse effect on human health and the environment. Exposure to some compounds may show both acute and chronic toxicity. There is a lack of knowledge on the effect of organic pro...Fire effluents, in most cases, have an adverse effect on human health and the environment. Exposure to some compounds may show both acute and chronic toxicity. There is a lack of knowledge on the effect of organic products on the human body in terms of the rate of organic material production in fires and their degree of toxicity. Thus, there is a need to expand the scope of studies about the organic products generated from fires and improve the methods of assessment to be included as part of fire hazard assessment. Different factors can be contributed to this lack of knowledge. For example, the composition of organic products generated from fires changes progressively and rapidly with progression of combustion and in a manner that is dependent on the fire condition. It is difficult to identify individual organic compounds produced during combustion. Another key factor is the lack of suitable instruments for measuring organic products generated from a fire. Also, the lack of procedures that are used to evaluate the lethal concentration limits and the lethal dose for a broad range of organic compounds generated from a fire may be another important factor which can be contributed to this lack of knowledge.展开更多
The influence of SO2 on the performance of Ag-Pd/Al2O3 for the selective catalytic reduction （SCR） of NOx with C2H5OH was investigated experimentally. The activity test results suggest that Ag-Pd/Al2O3 shows a small...The influence of SO2 on the performance of Ag-Pd/Al2O3 for the selective catalytic reduction （SCR） of NOx with C2H5OH was investigated experimentally. The activity test results suggest that Ag-Pd/Al2O3 shows a small activity loss in the presence of SO2 when using C2H5OH as a reductant. In situ DRIFTS spectra show that the activity loss originates from the formation of surface sulphate species on the Ag-Pd/Al2O3. The surface sulphate species formation inhibits the formation of nitrate, whereas hardly changes the partial oxidation of C2H5OH. Compared with the NOx reduction by C3H6, an obvious suppression of the surface sulphate species formation was observed by DRIFTS experiment when using C2H5OH as a reductant. This phenomenon reveals the better catalytic performance and strong SO2 tolerance of Ag-Pd/Al2O3-C2H50H system.展开更多
A novel graft copolymer consisting of polyisoprene backbone and hydrophilic side chain with carbamic acid ester functional group was prepared via thiol-ene＂click＂reaction and alcohol-isocyanate reactions.Polyisopren...A novel graft copolymer consisting of polyisoprene backbone and hydrophilic side chain with carbamic acid ester functional group was prepared via thiol-ene＂click＂reaction and alcohol-isocyanate reactions.Polyisoprene was synthesized by anionic polymerization using n-butyl lithium as initiator,and the pendant hydroxyl groups were introduced by the thiol-ene reaction of mercaptoethanol with the double bond of 1,2-addition units of PI backbone in the presence of radical initiator azobisisobutyronitrile. Isocyanate end group capped poly（ethylene glycol）（mPEG-NCO） was grafted onto the PI backbone through alcoholisocyanate reaction between the pendant hydroxyl groups and isocyanate group of mPEG-NCO.The structure of the graft copolymer were characterized and confirmed by means of size-exclusion chromatography,~1H NMR and FTIR spectroscopy.展开更多
Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stab...Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.展开更多
Several cyclic amino acids (1-4) were synthesized from glycine. Isocyanate ester was prepared as the key intermediate and reacted with dibromoalkanes to afford the target compounds.
文摘Isothiocyanates(ITCs)are an important class of organic compounds characterized by the functional group R-N=C=S.These functional groups are widely found in multiple natural products and pharmaceutical important drugs.Moreover,due to their high and versatile reactivity,they are widely used as an intermediate in organic synthesis.Keeping in view ITCs importance,this review summarizes their synthesis from nitrogen rich raw materials like amines,isocyanides,azides and some other compounds like oximes.Besides their synthesis,their application in organic compound synthesis as an intermediate will also be covered.Future research will likely focus on optimizing the synthesis of multifunctional isothiocyanates,understanding their complex biological mechanisms,exploring new applications,and highlighting the continued importance of isothiocyanates in modern chemistry and biotechnology.
基金This work was supported by the National Natural Science Foundation of China （No. 21173240）.
文摘Currently, industrial production of isocyanates, or diisocyanates in particular, has been exclusively based on phosgene processes. Phosgene is extremely toxic and large amounts of corrosive HC1 are produced as a side product. In the view of environment protection and society safety, development of non-phosgene processes for isocyanates production will be highly desired, and this should be one of the most important missions for green chemistry and catalysis. In this review, efforts for development of non-phosgene method for syntheses of isocyanates, i.e., catalytic syntheses of N-substituted carbamates from nitro- or amino-compounds with CO, dimethyl carbonate （DMC）, urea and even CO2 etc. as carbonyl sources, then thermal cracking of N-substituted carbamates to afford corresponding i socyanates, are summarized, and a brief prospect for non-phosgene syntheses of isocyanates is also addressed.
基金Funded by the National Key R&D Program of China(No.2022YFC3803400)。
文摘The effects of isocyanate(IA)incorporation on the toughness and volume stability of AAFS were systematically investigated.Various IA dosages were introduced into AAFS,and their influence on mechanical properties,microstructure,and shrinkage behavior was evaluated.The experimental results indicate that,with the incorporation of 5%IA,the 28-day compressive strength reaches 48.6 MPa,the 56-day drying shrinkage decreases by 35.91%,and minimal cracking is observed in the ring test.Microstructural analyses using SEM,XRD,and FTIR reveal that IA reacts with water to form urethane and biuret,which crosslinks into a durable network structure.This network fills pores,reducing internal stresses and improving both toughness and volume stability.These findings offer new insights into optimizing alkali-activated materials for construction applications and provide a potential pathway for the development of more durable and stable geopolymers.
基金financially supported by the National Natural Science Foundation of China (No.51974016)。
文摘Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety haz-ards during transportation and use. Therefore, it is necessary to develop gold leaching reagents that can replace cyanide. This paper intro-duces a method for synthesizing a gold leaching reagent. Sodium cyanate is used as the main raw material, with sodium hydroxide and so-dium ferrocyanide used as additives. The gold leaching reagent can be obtained under the conditions of a mass ratio of sodium cyanate,sodium hydroxide, and sodium ferrocyanide of 15:3:1, synthesis temperature of 600℃, and synthesis time of 1 h. This reagent has a goodrecovery effect on gold concentrate and gold-containing electronic waste. The gold leaching rate of roasted desulfurized gold concentratecan reach 87.56%. For the extraction experiments of three types of gold-containing electronic waste, the gold leaching rate can reach over90% after 2 h. Furthermore, the reagent exhibits good selectivity towards gold. Component analysis indicates that the effective compon-ent in the reagent could be sodium isocyanate.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20304011, 20774078 & 20434020)the Special Funds for Major Basic Research Projects (Grant No. 2005CB623802)
文摘The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes/triisobutyl aluminum (Ln(H<sub>2</sub>salen)<sub>2</sub>Cl<sub>3</sub>·2C<sub>2</sub>H<sub>7</sub>OH/Al(i-Bu)<sub>3</sub>) at room temperature was investigated. The influences of ligand structure, catalyst composition, polymerization temperature, polymerization time, the concentration of catalyst and monomer, and the polymerization solvent on the polymerization of isocyanates were studied. It was found that under the polymerization conditions, examined La(H<sub>2</sub>salen<sub>A</sub>)<sub>2</sub>Cl<sub>3</sub>·2C<sub>2</sub>-H<sub>7</sub>OH/Al(i-Bu)<sub>3</sub> (H<sub>2</sub>salen<sub>A</sub>= N,N′-disalicylideneethylene diamine) is a fairly high efficient catalyst for the polymerization of n-hexyl isocyanate (n-HexNCO) to prepare high molecular weight poly(n-hexyl isocyanate) (PHNCO) with narrower molecular weight distribution at room temperature. PHNCO could be prepared with yield of 74.0%, number-average molecular weight (M <sub>n</sub>) of 40.20×10<sup>4</sup> and MWD of 1.79 under the following optimum conditions: [Al]/[La] = 30 (molar ratio), [n-HexNCO]/[La] = 100 (molar ratio), [n-HexNCO] = 3.43 mol/L polymerization at 20°C for 12 h in toluene. In the same polymerization conditions, poly (n-octyl isocyanate) (PONCO) with yield of 67.3%, and poly(n-butyl isocyanate) (PBNCO) with yield of 45.5%, could be prepared respectively. The kinetics of the polymerization of n-HexNCO was also investigated and found to be first-order with respect to both monomer and catalyst concentrations.
基金Project supported by the National Natural Science Foundation of China and the Natural Science Foundation of Tianjin.
文摘The orientation of the addition of 5-amino-3-benzylthio-1,2,4-triazole and its analogues (pyrazole) (1) with the aryl isocyanate can be directed by controlling the reaction temperature and one of the product, 5-amino-1-arylaminocarbonyl-3-benzylthio-1,2,4-triazole (pyrazole) (2), can rearrange at 170C to another product, 5-arylureylene-3-benzylthio-1,2,4-triazole (pyrazole) (3). A plausible mechanism explanation for this rearrangement reaction was presented. It was suggested that the rearrangement reaction could be referred to the thermodynamics transposition leading to the predominant 5-arylureylene-3-benzylthio-1,2,4-triazole energy preferentially.
基金Project supported by the National Natural Science Foundation of China.
文摘The reaction of 3-substituted-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides with aryl isocyanate under different equivalents of strong base NaH was studied. Seventeen of new derivatives were obtained whose structures were characterized by H-1 NMR, IR, MS, elementary analysis and FeCl3 test.
基金financially supported by the Projects of the Research and Development Project of New Materials and Chemical Engineering Research Institute of Shanxi Zhejiang University(No.2021SX-AT010)the National Natural Science Foundation of China(No.21972103)Innovation and entrepreneurship training program for college students(No.202110112012)。
文摘Zeolite imidazole skeleton(ZIF-8)is a promising option for self-cleaning of building exterior walls due to its large specific surface area,high antibacterial activity and low biotoxicity.However,it suffers from low antibacterial efficiency and yield under visible light irradiation.To address the issues,we developed the photocatalytic materials T-ZIF-8-TDI(thermally treated-ZIF-8-toluene 2,4-diisocyanate)by modifying ZIF-8 with thermal oxygen sensitization and chemical bonding.The results show that the yield of T-ZIF-8-TDI photocatalytic antibacterial agent is increased to 11.5 times of that of T-ZIF-8,while maintaining the crystal structure of T-ZIF-8 and thermal stability up to 60℃.Furthermore,T-ZIF-8-TDI exhibits extended optical response range to the nearinfrared region,significantly narrowed band gap,improved photogenerated elec tron-hole separation efficiency,reduced recombination rate,and excellent photocatalytic performance.When the concentration of antibacterial agent is 600 mg·L^(-1),the antibacterial rate of Escherichia coli(E.coli)reaches 99.99%irradiated by visible light for30 min,and when the concentration of antibacterial agent is 200 mg·L^(-1),the antibacterial rate of Staphylococcus aureus(S.aureus)reaches 99.99%irradiated by visible light for 25 min.We also analyzed the reasons in detail from the aspects of bacterial species and antibacterial mechanism,and proposed the antibacterial mechanism of·O_(2)^(-)and h^(+)as the main active species.These findings suggest that T-ZIF-8-TDI photocatalytic antibacterial agent has potential for use in self-cleaning of building exterior walls.
文摘With the urgent shortage of forest resource in China, using agro-residues as raw materials of composite become increasingly important. Agro-residue is the most potential fiber resource, which is helpful to sustainable development of composite industries in China. Based on a great deal of researches, this paper summarized and discussed some problems in using agro-residues as raw materials of composites, including raw material preparation, hot-pressing, bonding technology, preventing composite from going moldy. It is proposed that to manufacture the composite of rice straws or wheat straws, the isocayante resin is a suitable adhesive, and the appropriate technologies, bonding, and treatment measures are also needed.
基金supported by Huazhong Agricultural University Scientific & Technological Self-innovation Foundation(Nos.2007XRC064 and 2008XKJC005)
文摘The carbodiimide 2,obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates,reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4（3H）-ones 4 and 5.The formation mechanism of the title compounds has been investigated.
基金This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil(CAPES)—Finance Code 001.Authors also acknowledge CNPq for financial support in special for the doctoral fellowship granted to G.S(CNPq Proc.140249/2017-6).AJFC acknowledge CNPq for research funding project#03847/2019-0.
文摘Oil spills and oil/water wastewater are among the great concerns regarding oil pollution.Existing technologies face many limitations and in some cases are responsible for causing secondary pollution,therefore there is as seek for environmental friendly solutions.Biomass,from which celluloses are highlighted,are being employed for oil/water separation or oil absorbents membranes.Usually,these membranes are obtained by freeze drying of CNF(cellulose nano-fibrils)suspensions followed by chemical modification for hydrophobization,which involves expensive process as chemical vapor deposition and expensive reactants as sylanes,turning these processes hardly scalable.Here,we produced a natural porous structure paper from eucalyptus pulp fibers modified by a dipping and heating process in a blocked diisocyanate solution.After the surface treatment,contact angle with water reached 144°and water absorption reduced seven times,keeping the good oil absorbance.The chemical modification process is simple to be performed and use a very low quantity of reactant estimated to be less than 0.1 wt%based on cellulose.The good mechanical properties of the material allows its use in non usual conditions which can be of great importance depending on the environmental conditions.
文摘In search of new anticancer agents, a series of novel 1-benzhydryl-4-(substituted phenylcarboxamide / carbothioamide)-1,4-diazepane derivatives were designed, synthesized and characterized using 1H NMR, LCMS and elemental analysis. These molecules were evaluated for their anti-cancer activity by trypan blue exclusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on B-cell leukemic cell line, Reh. Carboxamide moiety containing derivatives showed good activity compared to the corresponding carbothioamide derivatives. In particular, 4-benzhydryl-N-(3-chlorophenyl)-1,4-diazepane-1-carboxamide showed good activity with IC50 value of 18 μM.
基金supported by the National Natural Science Foundation of China(No.21573227,N0.11604052)the National Science Foundation of Anhui Province of China(No.1608085QA19)+2 种基金the Natural Science Research Project of Education Department of Anhui Province of China(No.2014KJ020)the Open Foundation of State Key Laboratory(No.SKLMRDK201503,No.SKLMRD-K201611,and No.SKLMRDK201711)the Doctoral Foundation of Fuyang Normal University(No.FSB201501005)
文摘The photodissociation dynamics of isocyanic acid （HNCO） has been studied by the time- sliced velocity map ion imaging technique at 193 nm. The NH（a1△） products were measured via （2＋1） resonance enhanced multiphoton ionization. Images have been accumulated for the NH（a1△） rotational states in the ground and vibrational excited state （v=0 and 1）. The center-of-mass translational energy distribution derived from the NH（a1△） images implies that the CO vibrational distributions are inverted for most of the measured 1NH（v｜j） internal states. The anisotropic product angular distribution observed indicates a rapid dissociation process for the N-C bond cleavage. A bimodal rotational state distribution of CO（v） has been observed, this result implies that isocyanic acid dissociates in the S1 state in two different pathways.
文摘The reaction of isocyanates with aliphatic and aromatic amines in the 1-n-butyl-3- methylimidazolium tetrafluoroborate (bmimBF4) ionic liquid in good to excellent yields is described. Due to its insolubility, the desired urea solids could be recovered by simple filtration from the ionic liquid after reaction.
文摘Polyamine-based scavenger resins containing 2, 3 and 4 nitrogen atoms have been prepared and their comparative efficacy to scavenge appropriate electrophilic chemicals (acids, acid chlorides, isocyanates and aldehydes) from solutions has been studied. As expected, the scavenging efficiency is directly proportional to the number of nucleophic nitrogens present on the resin. The results have been compared with the performance of the popular scavenger resin, namely, tris(2-aminoethyl)amine resin, to conclude that the low-cost polyamine resins now prepared can be conveniently used as effectively as the expensive commercial product.
文摘Fire effluents, in most cases, have an adverse effect on human health and the environment. Exposure to some compounds may show both acute and chronic toxicity. There is a lack of knowledge on the effect of organic products on the human body in terms of the rate of organic material production in fires and their degree of toxicity. Thus, there is a need to expand the scope of studies about the organic products generated from fires and improve the methods of assessment to be included as part of fire hazard assessment. Different factors can be contributed to this lack of knowledge. For example, the composition of organic products generated from fires changes progressively and rapidly with progression of combustion and in a manner that is dependent on the fire condition. It is difficult to identify individual organic compounds produced during combustion. Another key factor is the lack of suitable instruments for measuring organic products generated from a fire. Also, the lack of procedures that are used to evaluate the lethal concentration limits and the lethal dose for a broad range of organic compounds generated from a fire may be another important factor which can be contributed to this lack of knowledge.
基金The Key Program of the National Natural Science Foundation of China (No. 20437010) and the National Science Fund forDistinguished Young Scholars of China (No. 20425722)
文摘The influence of SO2 on the performance of Ag-Pd/Al2O3 for the selective catalytic reduction （SCR） of NOx with C2H5OH was investigated experimentally. The activity test results suggest that Ag-Pd/Al2O3 shows a small activity loss in the presence of SO2 when using C2H5OH as a reductant. In situ DRIFTS spectra show that the activity loss originates from the formation of surface sulphate species on the Ag-Pd/Al2O3. The surface sulphate species formation inhibits the formation of nitrate, whereas hardly changes the partial oxidation of C2H5OH. Compared with the NOx reduction by C3H6, an obvious suppression of the surface sulphate species formation was observed by DRIFTS experiment when using C2H5OH as a reductant. This phenomenon reveals the better catalytic performance and strong SO2 tolerance of Ag-Pd/Al2O3-C2H50H system.
基金supports of the Special Funds for Major Basic Research Projects (NoG2011CB606001)Zhejiang Provincial Top Key Discipline of New Materials and Process Engineering(No 20110926)
文摘A novel graft copolymer consisting of polyisoprene backbone and hydrophilic side chain with carbamic acid ester functional group was prepared via thiol-ene＂click＂reaction and alcohol-isocyanate reactions.Polyisoprene was synthesized by anionic polymerization using n-butyl lithium as initiator,and the pendant hydroxyl groups were introduced by the thiol-ene reaction of mercaptoethanol with the double bond of 1,2-addition units of PI backbone in the presence of radical initiator azobisisobutyronitrile. Isocyanate end group capped poly（ethylene glycol）（mPEG-NCO） was grafted onto the PI backbone through alcoholisocyanate reaction between the pendant hydroxyl groups and isocyanate group of mPEG-NCO.The structure of the graft copolymer were characterized and confirmed by means of size-exclusion chromatography,~1H NMR and FTIR spectroscopy.
基金The work cited in this review was supported by the National Natural Science Foundation of China (No, 928700801 and No 2880201)
文摘Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.
基金the National Natural Science Foundation of China(No.20272001)
文摘Several cyclic amino acids (1-4) were synthesized from glycine. Isocyanate ester was prepared as the key intermediate and reacted with dibromoalkanes to afford the target compounds.
