The chloromethylation reaction of substituted titanocenes (η~5-C_5H_5)(η~5-C_5H_4CRR'C_6H_4X)TiCl2 1 in the presence of polyformaldehyde and dry hydrogen chloride isreported.
The morphological change of St/DVB crosslinked gels during chloromethylation wasstudied by fluorescence spectroscopy using St/DVB crosslinked and hypercrosslinked gels as controlsamples. It has been found that with in...The morphological change of St/DVB crosslinked gels during chloromethylation wasstudied by fluorescence spectroscopy using St/DVB crosslinked and hypercrosslinked gels as controlsamples. It has been found that with increase of chlorine content, the excimer emission band (~325nm)approaches to vanish, while the intensity of multi-ring aggregate emission band (~420nm) quicklyreaches a maximum, and then decreases sharply accompanied by appearance ofa new broad bandcentred at ca 488nm which roughly coincides with the typical emission band of hypercrossllinkedSt/DVB gels. Mearwhile, the result of IR measurement suggests that methylene bridge between phenylrings forms and increases with chloromethylation process. These results are explained in terms ofaside reaction of post-crosslinking, which densifies the loosely crosslinked networks and undoes thedensely entangled microgel nuclei. As a result, the morphology of the crosslinked gels becom es morehomogeneous with chloromethylation.展开更多
The goal of this paper was to reveal the feasibility of chloromethylation of polymers made from technical divinylbenzene so as to introduce functional groups into polymeric adsorbents. For this study, the factors that...The goal of this paper was to reveal the feasibility of chloromethylation of polymers made from technical divinylbenzene so as to introduce functional groups into polymeric adsorbents. For this study, the factors that effect the chloromethylation reaction, such as the pore structure of the polymer, the ratio of the reactants to catalyst, the reaction temperature and reaction time and so on were investigated, and the pore structure and property of the chloromethylated polymers were studied. The results showed that polymers of technical divinylbenzene could be chloromethylated successfully, and the adsorptive property of the chloromethylated resin was different from that of the initial resin.展开更多
Ion segregation is critically important for achieving high ion conductivity for anion exchange membranes(AEMs).Herein,a new bisphenol monomer bearing ten electron-rich phenyl groups was designed and polymerized with v...Ion segregation is critically important for achieving high ion conductivity for anion exchange membranes(AEMs).Herein,a new bisphenol monomer bearing ten electron-rich phenyl groups was designed and polymerized with various amounts of electron-deficient 4,4′-dihydroxydiphenylsulfone and 4,4′-difluorobenzophenone to yield dense and selective reaction sites for chloromethylation and quaternization.As the most challenging step,chloromethylation was optimized by tuning the reaction temperature,reaction time,and reactant ratios.Ion exchange capacity,water uptake,anion conductivity,mechanical stability,and alkaline stability of the resulting AEMs were characterized in detail.It is found that chloromethylation reaction needed to be carried out at low equivalent of chloromethylation agents to avoid undesirable crosslinking.The QA-PAEKS-20 sample with an IEC of 1.19 mmol·g^-1 exhibited a Cl^–conductivity of 11.2 mS·cm^-1 and a water uptake of 30.2%at80°C,which are promising for AEM applications.展开更多
The chloromethylation reaction of 2-chloroethylbenzene was performed successfully by micellar ca-talysis in the biphasic oil/water system. The effects of anionic, cationic and non-ionic surfactants on the reaction wer...The chloromethylation reaction of 2-chloroethylbenzene was performed successfully by micellar ca-talysis in the biphasic oil/water system. The effects of anionic, cationic and non-ionic surfactants on the reaction were compared. The mechanism of chloromethylation reaction and the mechanism of micellar catalysis were investigated. The results show that the micellar catalysis is an effective way to realize the chloromethylation of 2-chloroethylbenzene, and the cationic surfactant shows the most effectiveness. The longer the hydrophobic chain of the cationic surfactant is, the better the catalysis effect will be, and the addition of inorganic electrolyte into the aqueous phase can markedly promote the catalysis effect.展开更多
This report details the properties of fluorine-containing anion exchange membranes(AEMs) synthesized by chloromethylation and quaternization of fluorinated poly(arylene ether)s(FPAEs) based on decafluorobiphenyl...This report details the properties of fluorine-containing anion exchange membranes(AEMs) synthesized by chloromethylation and quaternization of fluorinated poly(arylene ether)s(FPAEs) based on decafluorobiphenyl and bisphenol A. Meanwhile, we compared their properties with those of their non-fluorinated counterparts, Udel-based AEMs. The reactivity of the chloromethylation of fluorinated poly(arylene ether)s was lowered by the strong elec- tron-withdrawing group, per-fluorinated biphenyl residue. Therefore higher temperature, more chloromethylation reagent, and longer reaction time were needed in the chloromethylation of FPAEs. Because of the hydrophobicity of fluorine, the swelling of FPAEs was depressed. In the FPAE-based AEMs, the water uptake of FPAE-1 membrane(F-1) was just 30%. There is a strong correlation between water uptake and conductivity for both Udel- and FPAE-based AEMs. Among all the membranes, the water uptake and the conductivity of FPAE-3 membrane(F-3) could reach up to 100% and 13.47 mS/cm respectively at 30 ℃. The mechanical properties of FPAE-based AEMs at room tempera- ture were worse than those of Udel-based ones because of the weak intermolecular interaction caused by the low po- larizability of fluorine. However, their high temperature mechanical properties are better, which can be explained in terms of low swelling.展开更多
Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chlorometh...Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and chloroform. Quaternized poly(phthalazinone ether sulfone ketone) (QAPPESK) was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid (98%) and swollen in N,N-dimethylformamide (DMF). The vanadium redox flow battery (V-RFB) using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.展开更多
Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance...Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance of different ionic liquid catalysts for toluene chloromethylation was also studied. The reaction was found to proceed under mild conditions with excellent conversion (up to 90%) in the absence of Lewis acids. The ionic liquids could be recycled and reused without loss of their catalytic activities.展开更多
Two asymmetric porphyrins, 5-(4-chloromethylphenyl)-10, 15, 20-triphenyl porphyrin and 5-(4-formylphenyl)-10, 15, 20-triphenyl porphyrin, were successfully prepared by the symmetric meso-tetraphenyl porphyrin and rela...Two asymmetric porphyrins, 5-(4-chloromethylphenyl)-10, 15, 20-triphenyl porphyrin and 5-(4-formylphenyl)-10, 15, 20-triphenyl porphyrin, were successfully prepared by the symmetric meso-tetraphenyl porphyrin and relative molecular configurations and properties were characterized by spectral determinations. This work presented an example for synthesis of asymmetric porphyrin derivatives from the symmetric porphyrin. Both asymmetric porphyrins are reactive in molecular assembly, the concerned reactions including alkylation with Grignard reagents, etherification with alcohols, aldol condensation and Mannich reaction for modification and enhancing their functionality. In this work, the reaction conditions were improved, synthetic strategy and route were confirmed.展开更多
Chloromethylation of polystyrene (PS) with two different chloromethylating systems methylal/thionyl chloride and paraformaldehyde/trimethylchlorosilane was studied. Soluble chloromethylated polystyrene with a degree...Chloromethylation of polystyrene (PS) with two different chloromethylating systems methylal/thionyl chloride and paraformaldehyde/trimethylchlorosilane was studied. Soluble chloromethylated polystyrene with a degree of substitution of 89% was obtained. The Conant-Finkelstein reaction on the chloromethylated PS afforded soluble iodomethylated polystyrene with a degree of substitution as high as 96%. The reaction conditions of Minisci were employed to radically pyridinate PS via its iodomethylated derivative. Polyelectrolytes were formed which could be converted to normal polymers by treatment with a 20% aqueous solution of NaOH.展开更多
AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (D...AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (Deltapsim). METHODS: Cell culture, cell counting, ELISA assay, TUNEL, flow cytometry, Western blot and fluorometric assay were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanism. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Caspases 8 and 9 were activated during apoptosis as judged by the appearance of cleavage products from procaspase and the caspase activities to cleave specific fluorogenic substrates. To elucidate whether the activation of caspases 8 and 9 was required for the apoptosis induction, we examined the effect of caspase-specific inhibitors on apoptosis. The results showed that caspase inhibitors significantly inhibited the apoptosis induced by JTE-522. In addition, the membrane translocation of Bax and cytosolic release of cytochrome C accompanying with the decrease of the uptake of Rhodamin 123, were detected at an early stage of apoptosis. Furthermore, Bax translocation, cytochrome C release, and caspase 9 activation were blocked by Z-VAD.fmk and Z-IETD-CHO. CONCLUSION: The present data indicate a crucial association between activation of caspases 8, 9, cytochrome C release, membrane translocation of Bax, loss of Deltapsim and JTE-522-induced apoptosis in AGS cells.展开更多
Cationic ring-opening polymerization of 3,3-bis(chloromethyl)oxacyclobutane catalyzed by BF3.OEt2 was carded out in ionic liquids [bmim]BF4 and [bmim]PF6. The influences of BCMO concentration and molar ratio of BCMO...Cationic ring-opening polymerization of 3,3-bis(chloromethyl)oxacyclobutane catalyzed by BF3.OEt2 was carded out in ionic liquids [bmim]BF4 and [bmim]PF6. The influences of BCMO concentration and molar ratio of BCMO/BF3.OEt2 on the molecular weights and yield of PBCMO were investigated. The polymerization in ionic liquids proceed to high conversions, although molecular weights are limited, similar to polymerization in organic solvent such as CH2Cl2. Follow a viewpoint of green chemistry, we feel ionic liquid [bmim]BF4 is superior to [bmim]PF6. Extracting [bmim]PF6 from the product using organic solvent as extractant limits its advantage as a green reaction media.展开更多
Ring opening polymerization of (chloromethyl) thiirane (CMT) usingrare earth coordination catalysts has been investigated for the first time: Ithas been found that binary rare earth coordination catalyst composed of r...Ring opening polymerization of (chloromethyl) thiirane (CMT) usingrare earth coordination catalysts has been investigated for the first time: Ithas been found that binary rare earth coordination catalyst composed of rareof phosphonate and trialkyl aluminum are effective catalysts for the polymerization of (chloromethyl)thiirane with high yield. Kinetic studies showed that the polymerization rate is of first order with respect to both monomer concentration and catalyst concentration. The antivation energy of the polyimerization reaction is 28.4kJ/mol.展开更多
A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared. The degree of functionalization with aldehyde groups is well suited for the subseq...A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared. The degree of functionalization with aldehyde groups is well suited for the subsequent use of the products as Wittig reagents. The polymer bound aldehyde was reacted with Wittig reagents to give olefin groups grafted on styrene-divinylbenzene copolymers. The reactions were carded out in phase transfer catalysis conditions. A simple procedure for the calculation of the degree of functionalization and the statistical modeling of the structural repetitive unit of the copolymer are reported.展开更多
The suspension polymerization with two organic phases was adopted to prepare spherical hyper- crosslinked resin by self-polycondensation of 4,4'-bis-(chloromethyl)- 1, 1'-biphenyl (CMB). The chemical structure,m...The suspension polymerization with two organic phases was adopted to prepare spherical hyper- crosslinked resin by self-polycondensation of 4,4'-bis-(chloromethyl)- 1, 1'-biphenyl (CMB). The chemical structure,morphology and pore characteristics of the novel spherical resin were characterized with Fourier transform infrared spectroscopy (FTIR), micrograph and Brunauer-Emmett-Teller (BET). It is found that the suspension system and stirring speed impose a great influence upon the regularity and size distribution of hypercrosslinked beads. To prepare CMB resin beads with diameter of about 300 μm, the optimal condition is as follows: stirring speed 300 r·min^-1, and the volume ratio of the two organic phases (nitrobenzene/dimethyl silicon oil) 1 : 5. After the self-polycondensation and sqccedent post-crosslinking of CMB monomer, the spherical adsorbent presents high spec^al surface area (1190 m^2· g^-1) and abundant pore^volume (0.714 cm^3· g^-1), and could be potentially applied qn the adsorption of various organic molecules and synthesis of porous ion exchanger.展开更多
2-(Chloromethyl)furan as an electrophile attacks lithium trialkylalkynylborates,followed by the oxidation with H_2O_2 under basic conditions to afford 2-furfurylketones in good yields.
Several kinds of chloromethyl polysulfones (CMPF) with different chlorinity and reactive groups were synthesized by Friedel.crafts reaction, which could be utilized as reactively matrix membrane materials. The CMPF ...Several kinds of chloromethyl polysulfones (CMPF) with different chlorinity and reactive groups were synthesized by Friedel.crafts reaction, which could be utilized as reactively matrix membrane materials. The CMPF hollow matrix membranes were prepared with phase inversion by utilization of CMPF/additive/DMAC casting solution and CMPF as membrane materials. It was found that the effects of additive content, bore liquid and dry spinning distance on the structure of CMPF hollow fiber matrix membrane were different. A high qualified palysulfone hollow fiber chelating membrane modified with thiourea as chelating groups was prepared using CMPF as membrane matrix materials, through the reaction between thiourea and CMPF hollow fiber matrix membrane to afford the methyl iso-thiourium polysulfone. The experimental results showed that thermal drawing could increase the mechanical properties of matrix membrane, and the thermal treatment could increase the homogeneity and stability of the structure of polysulfoue hollow fiber chelating membrane modified with thiourea.展开更多
A number of chlorumethylated polystyrenes were synthesized and tried to immobilize aminoacylase from Aspergillus oryzae and many factors which affected immobilized enzyme activity were studied in detail. The results i...A number of chlorumethylated polystyrenes were synthesized and tried to immobilize aminoacylase from Aspergillus oryzae and many factors which affected immobilized enzyme activity were studied in detail. The results indicated that the immobilized enzyme on support(IAR-1) possessed high enzymatic activity and high stability.展开更多
The Ziegler-Natta type catalytic systems composed of lanthanide compound and ethyl aluminum sesquichloride are effective to convert chloromethyl thiirane to polymer of molecular weight ca. 10,000. The effects of rare ...The Ziegler-Natta type catalytic systems composed of lanthanide compound and ethyl aluminum sesquichloride are effective to convert chloromethyl thiirane to polymer of molecular weight ca. 10,000. The effects of rare earth element and ligand were studied.展开更多
With well-defined channels and tunable functionality, metal-organic frameworks (MOFs) have inspired the design of a new class of ion-conductive compounds. In contrast to the extensive studies on proton- conductive M...With well-defined channels and tunable functionality, metal-organic frameworks (MOFs) have inspired the design of a new class of ion-conductive compounds. In contrast to the extensive studies on proton- conductive MOFs and related membranes attractive for fuel cells, rare reports focus on MOFs in preparation of anion exchange membranes. In this study, chloromethylated MIL-101 (Cr) was prepared and incor- porated into chloromethylated poly (ether ether ketone) (PEEK) as a multifunctional filler to prepare imidazolium PEEK/imidazolium MIL-101(Cr) (ImPEEK/ImMIL-101(Cr)) anion exchange membrane after synchronous quaternization. The successful synthesis and chloromethylation of MIL-101(Cr) were veri- fied by transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy while the enhanced performance of composite membranes in hydroxide conductivity, mechanical strength and dimensional stability were evaluated by alternating-current impedance, electronic stretching machine and measurement of swelling ratio. Specifically, incorporating 5.0wt% ImMIL-101(Cr) afforded a 71.4% increase in hydroxide conductivity at 20℃, 100% RH. Besides, the composite membranes exhibited enhanced dimensional stability and mechanical strength due to the rigid framework of ImMIL- 101(Cr). At room temperature and the ImM1L-101(Cr) content of 10wt%, the swelling ratio of the ImPEEK/lmMIL-101(Cr) was 70.04% lower while the tensile strength was 47.5% higher than that of the pure membrane.展开更多
文摘The chloromethylation reaction of substituted titanocenes (η~5-C_5H_5)(η~5-C_5H_4CRR'C_6H_4X)TiCl2 1 in the presence of polyformaldehyde and dry hydrogen chloride isreported.
基金National Natural Scientific Foundation of China (Project grant No.29574165 29928003+1 种基金 29874019) National Natural Scientific Foundation of Tianjin (Project grant No.013604011)
文摘The morphological change of St/DVB crosslinked gels during chloromethylation wasstudied by fluorescence spectroscopy using St/DVB crosslinked and hypercrosslinked gels as controlsamples. It has been found that with increase of chlorine content, the excimer emission band (~325nm)approaches to vanish, while the intensity of multi-ring aggregate emission band (~420nm) quicklyreaches a maximum, and then decreases sharply accompanied by appearance ofa new broad bandcentred at ca 488nm which roughly coincides with the typical emission band of hypercrossllinkedSt/DVB gels. Mearwhile, the result of IR measurement suggests that methylene bridge between phenylrings forms and increases with chloromethylation process. These results are explained in terms ofaside reaction of post-crosslinking, which densifies the loosely crosslinked networks and undoes thedensely entangled microgel nuclei. As a result, the morphology of the crosslinked gels becom es morehomogeneous with chloromethylation.
文摘The goal of this paper was to reveal the feasibility of chloromethylation of polymers made from technical divinylbenzene so as to introduce functional groups into polymeric adsorbents. For this study, the factors that effect the chloromethylation reaction, such as the pore structure of the polymer, the ratio of the reactants to catalyst, the reaction temperature and reaction time and so on were investigated, and the pore structure and property of the chloromethylated polymers were studied. The results showed that polymers of technical divinylbenzene could be chloromethylated successfully, and the adsorptive property of the chloromethylated resin was different from that of the initial resin.
基金financially supported by the National Natural Science Foundation of China (Nos. 51873037 and 51503038)
文摘Ion segregation is critically important for achieving high ion conductivity for anion exchange membranes(AEMs).Herein,a new bisphenol monomer bearing ten electron-rich phenyl groups was designed and polymerized with various amounts of electron-deficient 4,4′-dihydroxydiphenylsulfone and 4,4′-difluorobenzophenone to yield dense and selective reaction sites for chloromethylation and quaternization.As the most challenging step,chloromethylation was optimized by tuning the reaction temperature,reaction time,and reactant ratios.Ion exchange capacity,water uptake,anion conductivity,mechanical stability,and alkaline stability of the resulting AEMs were characterized in detail.It is found that chloromethylation reaction needed to be carried out at low equivalent of chloromethylation agents to avoid undesirable crosslinking.The QA-PAEKS-20 sample with an IEC of 1.19 mmol·g^-1 exhibited a Cl^–conductivity of 11.2 mS·cm^-1 and a water uptake of 30.2%at80°C,which are promising for AEM applications.
文摘The chloromethylation reaction of 2-chloroethylbenzene was performed successfully by micellar ca-talysis in the biphasic oil/water system. The effects of anionic, cationic and non-ionic surfactants on the reaction were compared. The mechanism of chloromethylation reaction and the mechanism of micellar catalysis were investigated. The results show that the micellar catalysis is an effective way to realize the chloromethylation of 2-chloroethylbenzene, and the cationic surfactant shows the most effectiveness. The longer the hydrophobic chain of the cationic surfactant is, the better the catalysis effect will be, and the addition of inorganic electrolyte into the aqueous phase can markedly promote the catalysis effect.
基金Supported by the National Natural Science Foundation of China(Nos.51173178, 514"73157, 21304093).
文摘This report details the properties of fluorine-containing anion exchange membranes(AEMs) synthesized by chloromethylation and quaternization of fluorinated poly(arylene ether)s(FPAEs) based on decafluorobiphenyl and bisphenol A. Meanwhile, we compared their properties with those of their non-fluorinated counterparts, Udel-based AEMs. The reactivity of the chloromethylation of fluorinated poly(arylene ether)s was lowered by the strong elec- tron-withdrawing group, per-fluorinated biphenyl residue. Therefore higher temperature, more chloromethylation reagent, and longer reaction time were needed in the chloromethylation of FPAEs. Because of the hydrophobicity of fluorine, the swelling of FPAEs was depressed. In the FPAE-based AEMs, the water uptake of FPAE-1 membrane(F-1) was just 30%. There is a strong correlation between water uptake and conductivity for both Udel- and FPAE-based AEMs. Among all the membranes, the water uptake and the conductivity of FPAE-3 membrane(F-3) could reach up to 100% and 13.47 mS/cm respectively at 30 ℃. The mechanical properties of FPAE-based AEMs at room tempera- ture were worse than those of Udel-based ones because of the weak intermolecular interaction caused by the low po- larizability of fluorine. However, their high temperature mechanical properties are better, which can be explained in terms of low swelling.
基金partly financed by the Major State Basic Research Development Program of China(No.2003 CB615700)the National Natural Science Foundation of China(No.20604005).
文摘Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and chloroform. Quaternized poly(phthalazinone ether sulfone ketone) (QAPPESK) was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid (98%) and swollen in N,N-dimethylformamide (DMF). The vanadium redox flow battery (V-RFB) using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.
基金Supported by the National Natural Science Foundation of China (20376015), the Natural Science Foundation of Guangdong Province (32491) and Guangzhou Project of Science & Technology (2004J1-C0151).
文摘Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance of different ionic liquid catalysts for toluene chloromethylation was also studied. The reaction was found to proceed under mild conditions with excellent conversion (up to 90%) in the absence of Lewis acids. The ionic liquids could be recycled and reused without loss of their catalytic activities.
文摘Two asymmetric porphyrins, 5-(4-chloromethylphenyl)-10, 15, 20-triphenyl porphyrin and 5-(4-formylphenyl)-10, 15, 20-triphenyl porphyrin, were successfully prepared by the symmetric meso-tetraphenyl porphyrin and relative molecular configurations and properties were characterized by spectral determinations. This work presented an example for synthesis of asymmetric porphyrin derivatives from the symmetric porphyrin. Both asymmetric porphyrins are reactive in molecular assembly, the concerned reactions including alkylation with Grignard reagents, etherification with alcohols, aldol condensation and Mannich reaction for modification and enhancing their functionality. In this work, the reaction conditions were improved, synthetic strategy and route were confirmed.
文摘Chloromethylation of polystyrene (PS) with two different chloromethylating systems methylal/thionyl chloride and paraformaldehyde/trimethylchlorosilane was studied. Soluble chloromethylated polystyrene with a degree of substitution of 89% was obtained. The Conant-Finkelstein reaction on the chloromethylated PS afforded soluble iodomethylated polystyrene with a degree of substitution as high as 96%. The reaction conditions of Minisci were employed to radically pyridinate PS via its iodomethylated derivative. Polyelectrolytes were formed which could be converted to normal polymers by treatment with a 20% aqueous solution of NaOH.
基金National Natural Science Foundation of China,No.39770300,30070873the Overseas Chinese Affairs Office of the State Council Foundation,No.98-33
文摘AIM: To investigate the role of the mitochondrial pathway in JTE-522-induced apoptosis and to investigate the relationship between cytochrome C release, caspase activity and loss of mitochondrial membrane potential (Deltapsim). METHODS: Cell culture, cell counting, ELISA assay, TUNEL, flow cytometry, Western blot and fluorometric assay were employed to investigate the effect of JTE-522 on cell proliferation and apoptosis in AGS cells and related molecular mechanism. RESULTS: JTE-522 inhibited the growth of AGS cells and induced the apoptosis. Caspases 8 and 9 were activated during apoptosis as judged by the appearance of cleavage products from procaspase and the caspase activities to cleave specific fluorogenic substrates. To elucidate whether the activation of caspases 8 and 9 was required for the apoptosis induction, we examined the effect of caspase-specific inhibitors on apoptosis. The results showed that caspase inhibitors significantly inhibited the apoptosis induced by JTE-522. In addition, the membrane translocation of Bax and cytosolic release of cytochrome C accompanying with the decrease of the uptake of Rhodamin 123, were detected at an early stage of apoptosis. Furthermore, Bax translocation, cytochrome C release, and caspase 9 activation were blocked by Z-VAD.fmk and Z-IETD-CHO. CONCLUSION: The present data indicate a crucial association between activation of caspases 8, 9, cytochrome C release, membrane translocation of Bax, loss of Deltapsim and JTE-522-induced apoptosis in AGS cells.
基金financially supported by the Key Project of Chinese Ministry of Education(No.105075)the National Natural Science Foundation of China(No.20503016).
文摘Cationic ring-opening polymerization of 3,3-bis(chloromethyl)oxacyclobutane catalyzed by BF3.OEt2 was carded out in ionic liquids [bmim]BF4 and [bmim]PF6. The influences of BCMO concentration and molar ratio of BCMO/BF3.OEt2 on the molecular weights and yield of PBCMO were investigated. The polymerization in ionic liquids proceed to high conversions, although molecular weights are limited, similar to polymerization in organic solvent such as CH2Cl2. Follow a viewpoint of green chemistry, we feel ionic liquid [bmim]BF4 is superior to [bmim]PF6. Extracting [bmim]PF6 from the product using organic solvent as extractant limits its advantage as a green reaction media.
文摘Ring opening polymerization of (chloromethyl) thiirane (CMT) usingrare earth coordination catalysts has been investigated for the first time: Ithas been found that binary rare earth coordination catalyst composed of rareof phosphonate and trialkyl aluminum are effective catalysts for the polymerization of (chloromethyl)thiirane with high yield. Kinetic studies showed that the polymerization rate is of first order with respect to both monomer concentration and catalyst concentration. The antivation energy of the polyimerization reaction is 28.4kJ/mol.
文摘A chloromethylated styrene-divinylbenzene copolymer support system functionalized with 4-benzaldehyde and 2-benzaldehyde was prepared. The degree of functionalization with aldehyde groups is well suited for the subsequent use of the products as Wittig reagents. The polymer bound aldehyde was reacted with Wittig reagents to give olefin groups grafted on styrene-divinylbenzene copolymers. The reactions were carded out in phase transfer catalysis conditions. A simple procedure for the calculation of the degree of functionalization and the statistical modeling of the structural repetitive unit of the copolymer are reported.
基金Supported by the National Natural Science Foundation of China (21004055) and the Doctoral Discipline Foundation of Education Ministry (20104101110005).
文摘The suspension polymerization with two organic phases was adopted to prepare spherical hyper- crosslinked resin by self-polycondensation of 4,4'-bis-(chloromethyl)- 1, 1'-biphenyl (CMB). The chemical structure,morphology and pore characteristics of the novel spherical resin were characterized with Fourier transform infrared spectroscopy (FTIR), micrograph and Brunauer-Emmett-Teller (BET). It is found that the suspension system and stirring speed impose a great influence upon the regularity and size distribution of hypercrosslinked beads. To prepare CMB resin beads with diameter of about 300 μm, the optimal condition is as follows: stirring speed 300 r·min^-1, and the volume ratio of the two organic phases (nitrobenzene/dimethyl silicon oil) 1 : 5. After the self-polycondensation and sqccedent post-crosslinking of CMB monomer, the spherical adsorbent presents high spec^al surface area (1190 m^2· g^-1) and abundant pore^volume (0.714 cm^3· g^-1), and could be potentially applied qn the adsorption of various organic molecules and synthesis of porous ion exchanger.
基金Project Supported by the National Natural Science Foundation of China
文摘2-(Chloromethyl)furan as an electrophile attacks lithium trialkylalkynylborates,followed by the oxidation with H_2O_2 under basic conditions to afford 2-furfurylketones in good yields.
基金Supported by the Natural Science Foundation of Tianjin (No.05YFJ MJC04200)
文摘Several kinds of chloromethyl polysulfones (CMPF) with different chlorinity and reactive groups were synthesized by Friedel.crafts reaction, which could be utilized as reactively matrix membrane materials. The CMPF hollow matrix membranes were prepared with phase inversion by utilization of CMPF/additive/DMAC casting solution and CMPF as membrane materials. It was found that the effects of additive content, bore liquid and dry spinning distance on the structure of CMPF hollow fiber matrix membrane were different. A high qualified palysulfone hollow fiber chelating membrane modified with thiourea as chelating groups was prepared using CMPF as membrane matrix materials, through the reaction between thiourea and CMPF hollow fiber matrix membrane to afford the methyl iso-thiourium polysulfone. The experimental results showed that thermal drawing could increase the mechanical properties of matrix membrane, and the thermal treatment could increase the homogeneity and stability of the structure of polysulfoue hollow fiber chelating membrane modified with thiourea.
文摘A number of chlorumethylated polystyrenes were synthesized and tried to immobilize aminoacylase from Aspergillus oryzae and many factors which affected immobilized enzyme activity were studied in detail. The results indicated that the immobilized enzyme on support(IAR-1) possessed high enzymatic activity and high stability.
文摘The Ziegler-Natta type catalytic systems composed of lanthanide compound and ethyl aluminum sesquichloride are effective to convert chloromethyl thiirane to polymer of molecular weight ca. 10,000. The effects of rare earth element and ligand were studied.
基金supported by the National Science Fund for Distinguished Young Scholars(21125627)the National Natural Science Founds of China(21490583 and 21621004)the Program of Introducing Talents of Discipline to Universities(B06006).
文摘With well-defined channels and tunable functionality, metal-organic frameworks (MOFs) have inspired the design of a new class of ion-conductive compounds. In contrast to the extensive studies on proton- conductive MOFs and related membranes attractive for fuel cells, rare reports focus on MOFs in preparation of anion exchange membranes. In this study, chloromethylated MIL-101 (Cr) was prepared and incor- porated into chloromethylated poly (ether ether ketone) (PEEK) as a multifunctional filler to prepare imidazolium PEEK/imidazolium MIL-101(Cr) (ImPEEK/ImMIL-101(Cr)) anion exchange membrane after synchronous quaternization. The successful synthesis and chloromethylation of MIL-101(Cr) were veri- fied by transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy while the enhanced performance of composite membranes in hydroxide conductivity, mechanical strength and dimensional stability were evaluated by alternating-current impedance, electronic stretching machine and measurement of swelling ratio. Specifically, incorporating 5.0wt% ImMIL-101(Cr) afforded a 71.4% increase in hydroxide conductivity at 20℃, 100% RH. Besides, the composite membranes exhibited enhanced dimensional stability and mechanical strength due to the rigid framework of ImMIL- 101(Cr). At room temperature and the ImM1L-101(Cr) content of 10wt%, the swelling ratio of the ImPEEK/lmMIL-101(Cr) was 70.04% lower while the tensile strength was 47.5% higher than that of the pure membrane.