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本文以季磷盐作相转移催化剂,对二苯基二苄基季磷盐及二苯基二乙基季磷盐与对位取代苯甲醛的PTC-Wittig反应进行了研究。 相似文献
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研究发现二元酸酯PVC膜电极对季鏻和季鉮盐均具有能斯特响应。电极的响应机理是由于季鏻、季鉮阳离子的正电中心与电子云密度较大的酯中苯环产生次级力作用所致。 相似文献
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本文以交联的氯甲基化聚苯乙烯树脂为原料,合成了四种类型的含两个带α-H碳原子的季鏻盐树脂(Ⅰ)、(Ⅱ)、(Ⅲ)、(Ⅳ),它们在碱的作用下,与醛的Wittig反应表现出不同的位置选择性:季鏻盐树脂(Ⅰ)和(Ⅳ)与醛反应只生成带烯键的聚合物;季鏻盐树脂(Ⅲ)与醛反应只生成低分子烯烃产物;而季鏻盐树脂(Ⅱ)与醛反应则生成低分子烯烃产物又生成带烯键的聚合物。 相似文献
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与铵盐类离子液体比较,季鏻盐离子液体具有挥发性更低,物理、化学性质更加稳定,兼具催化功能等优点。近年来,季鏻盐离子液体作为一种绿色反应介质日益受到重视,很多类型的有机反应在季鏻盐离子液体中得到应用,收到了很好的效果。本文主要以2000年以来的期刊文献报道为线索,对季鏻盐离子液体的制备方法以及以其作为反应介质的绿色有机反应进行了综述。这些反应主要包括Diels-Alder反应、Heck反应、Suzuki反应、Buchwald-Hartwig 反应、Friedel-Crafts反应、Kornblum 取代反应、Grignard反应、羰基化反应、氢甲酰化反应、转移氢化反应、酯化反应等多种类型。特别是对于一些涉及强碱性反应条件或亲电取代的反应类型,季鏻盐离子液体具有特殊的优势。 相似文献
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合成了1种苄基三苯基季鏻盐——氯化苄基三苯基季鏻盐([BzTPP]+Cl-);利用元素分析、红外光谱、电子喷雾质谱和X射线单晶衍射对其进行了组成分析和结构表征;采用二倍稀释法测定了其抗菌活性,并与季鏻盐[BzTPP]2[CoCl4]和[BzTPP]2[MnCl4]进行了对比.结果表明,合成的季鏻盐[BzTPP]+Cl-属于正交晶系,Pbca空间群,晶胞参数为:a=1.388 0(1)nm,b=1.717 0(2)nm,c=1.817 5(2)nm,α=β=γ=90°,V=4.131 3(7)nm3,Z=8,Dc=1.191g/cm3,GOOF=1.002,R1=0.038 4,wR2=0.113 6.该季鏻盐由Cl-离子和[BzTPP]+阳离子组成,阴、阳离子之间存在C-H…Cl氢键.与此同时,三种季鏻盐对大肠杆菌、金葡萄球菌及沙门氏菌均具有较好的抗菌活性. 相似文献
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一种新型胍盐抗菌剂的制备及其性能研究 总被引:1,自引:0,他引:1
采用盐酸胍盐、六亚甲基二胺、二乙基三胺和环氧氯丙烷为原料合成了一种新型的胍盐抗菌剂,使其同时起到抗菌和提高纸页湿强度的作用。用二维核磁共振谱(HH-COSY)对胍盐抗菌剂的结构进行了表征,同时研究了胍盐抗菌剂对大肠杆菌的最低抑菌浓度和对纸张的增湿强效果。通过UV吸收法和激光共聚焦显微镜对胍盐抗菌剂的抗菌机理进行了进一步的研究,结果表明,胍盐抗菌剂主要是通过先破坏细菌的细胞膜,然后引起细胞内的物质流出细胞,从而抑制细菌的生长繁殖。 相似文献
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The preparation and the releasing behavior of modified silica coatings, containing embedded biocides on textiles, were compared and assessed with regard to application parameters like antimicrobial efficacy, wash-out and long-term behavior. For this, silica layers with embedded silver, silver salts and biocidal quaternary ammonium salts (cetyltrimethylammoniumbromid and octenidine) were investigated. Both the growth of fungi and bacteria can be inhibited by coatings with embedded biocides. Especially by using octenidine, an excellent long-term inhibition of fungi growth can be reached. 相似文献
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水溶性壳聚糖降血脂作用的化学机理(Ⅰ)──水溶性壳聚糖及其衍生物对胆酸盐的结合能力研究 总被引:15,自引:0,他引:15
通过壳聚糖氧化裂解,制备了分子量为8000的水溶性壳聚糖,并通过烷基化反应合成了二乙氨乙基壳聚糖、二甲氨基(1-甲基)乙基壳聚糖及二乙基甲基铵乙基壳聚糖.在体外测定了水溶性壳聚糖及其衍生物对胆酸盐(牛磺胆酸钠和甘氨胆酸钠)的结合能力及其影响因素.结果表明,水溶性壳聚糖结合胆酸盐的能力主要取决于其阳离子化程度.修饰后的壳聚糖结合胆酸盐的能力增强,说明引入更多的胺基或铵基有利于对胆酸盐的结合. 相似文献
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Jumpei Kawada Yasuo Abe Toshifumi Yui Kenji Okuyama Kozo Ogawa 《Journal of carbohydrate chemistry》2013,32(5):559-571
ABSTRACT Spontaneous removal of monocarboxylic (formic, acetic, propionic or butyric) acids accompanying dehydration of the corresponding chitosan salts was observed from X-ray fiber diffraction diagrams obtained during the storage of these salts for a given period of time. The first three salts were prepared by immersing a tendon chitosan (a hydrated crystal) in an aqueous solution of respective monocarboxylic acid and 2-propanol. The salts showed similar fiber patterns not only to one another but also to the “Eight-fold” polymorph of the original chitosan, indicating that they are Type II salts, hydrated crystals, where the backbone chitosan molecule takes up an eight-fold helical conformation. The temperature required for the salt formation depended on the hydrophobicity of the acid, e.g., the chitosan formic acid salt could be prepared at room temperature, whereas, formation of the propionic acid salt was carried out at 4 °C. All the acids spontaneously evaporated accompanied by dehydration during storage of the salts, resulting in formation of anhydrous crystalline chitosan. Removal of the monocarboxylic acids was accelerated by increasing the hydrophobicity of the acid: at 100% relative humidity approximately 3 months for the formic, 1 month for the acetic and 3 weeks for the propionic acid salts. In the case of butyric acid the anhydrous polymorph of chitosan was obtained immediately after the reaction, suggesting that the water removing action of this acid was too fast to detect a Type II salt by the present X-ray method. The anhydrous crystals of chitosan were irreversibly prepared by annealing a hydrated crystal in water at a high temperature, such as 240 °C, leading to a little loss of orientation and to thermal decomposition of the sample specimen to some extent. But it was found that, through Type II salts of monocarboxylic acids, the hydrated crystals of chitosan can be dehydrated even at room temperature without any loss of orientation and decomposition of the chitosan specimen. 相似文献
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Kuca K Marek J Stodulka P Musilek K Hanusova P Hrabinova M Jun D 《Molecules (Basel, Switzerland)》2007,12(10):2341-2347
Benzalkonium salts are widely used as disinfectants, biocides and detergents,among a variety of other applications. The cationic surface-activity of these salts determines their potential to act as a biocide on both target and non-target organisms. In this study, a quick synthesis of a complete set of the benzalkonium salts differing in the length of an alkylating chain (from C(2) to C(20)) is described. Moreover, their (1)H-NMR, HPLC-MS, TLC and HPLC analysis were recorded. 相似文献
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Akihiko Kanazawa Tomiki Ikeda Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1993,31(12):3003-3011
Polyesters were prepared which retained phosphonium biocides as counter ions of sodium sulfonate moieties incorporated into the polymers, and surface antibacterial activity of the polyester films against Staphylococcus aureus and Escherichia coli was explored. These films exhibited a high surface antibacterial activity against S. aureus and E. coli, particularly against S. aureus, and the activity was affected by the structure and the compositional ratio of the phosphonium salts. Amount of the released phosphonium salts was very small, so that liberation of the phosphonium biocides can be expected to occur over a long period. Morphological changes of the cells of S. aureus and E. coli in contact with the polyester films were evaluated by scanning electron microscopy. It was found that the surface antibacterial activity of the polyester films was rather bacteriostatic than bactericidal as evidenced by no morphological changes of the bacterial cells in contact with the phosphonium biocides © 1993 John Wiley & Sons, Inc. 相似文献
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Neira-Carrillo A Yazdani-Pedram M Retuert J Diaz-Dosque M Gallois S Arias JL 《Journal of colloid and interface science》2005,286(1):134-141
The biopolymer chitosan was chemically modified by grafting polyacrylamide or polyacrylic acid in a homogeneous aqueous phase using potassium persulfate (KPS) as redox initiator system in the presence of N,N-methylene-bis-acrylamide as a crosslinking agent. The influence of the grafted chitosan on calcium salts crystallization in vitro was studied using the sitting-drop method. By using polyacrylamide grafted chitosan as substrate, rosette-like CaSO4 crystals were observed. This was originated by the presence of sulfate coming from the initiator KPS. By comparing crystallization on pure chitosan and on grafted chitosan, a dramatic influence of the grafted polymer on the crystalline habit of both salts was observed. Substrates prepared by combining sulfate with chitosan or sulfate with polyacrylamide did not produce similar CaSO4 morphologies. Moreover, small spheres or donut-shaped CaCO3 crystals on polyacrylic acid grafted chitosan were generated. The particular morphology of CaCO3 crystals depends also on other synthetic parameters such as the molecular weight of the chitosan sample and the KPS concentration. 相似文献
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Akihiko Kanazawa Tomiki Ikeda Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1993,31(6):1467-1472
Immobilized polycationic biocides with phosphonium salt on the surface of poly(propylene) film were prepared by surface photografting and surface antibacterial activity of the resulting films against Staphylococcus aureus and Escherichia coli was explored by the viable cell counting method. These films with phosphonium salts were found to exhibit high antibacterial activity against S. aureus and E. coli—particularly against E. coli. Furthermore, morphological changes of the cells of S. aureus and E. coli in contact with the immobilized phosphonium salt were estimated by scanning electron microscopy. It was found that the immobilized biocides exhibited surface bactericidal activity against both strains as evidenced by shrunken and deformed cells of these species in contact with the immobilized biocides. © 1993 John Wiley & Sons, Inc. 相似文献
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The structural and electric properties of chitosan electrolytes doped by three different ammonium salts [CH3COONH4, NH4Cl, and (NH4)2SO4] were discussed. The chitosan electrolytes were prepared by solution casting technique. The results show that the addition of ammonium salts leads to: The formation of complexation between ammonium salts and chitosan matrix, the destruction of crystal forms, and the enhancement of amorphous nature. With the rise of salt content, both the glass transition temperature and the activation energy show a “V”‐type trend, whereas the conductivity exhibits a reverse trend. For different ammonium salts, the electric properties of the chitosan electrolyte are different due to the Coulomb force between anion of salts and functional groups. The CH3COONH4 doped chitosan electrolyte exhibits the optimum electric properties, whereas those of (NH4)2SO4 doped chitosan electrolyte are worst. The chitosan electrolyte doped with 40 wt % CH3COONH4 has the lowest glass transition temperature of 369 K, the lowest activation energy of 0.19 eV, and the highest ionic conductivity of 2.87 × 10?4 S cm?1 at room temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 880–885, 2010 相似文献
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T. S. Demina T. A. Akopova L. V. Vladimirov A. N. Shchegolikhin A. S. Kechek’yan N. S. Perov A. O. Chernyshenko A. N. Zelenetskii 《Polymer Science Series B》2011,53(5-6):358-370
New polymer salts and N-acetylated chitosan derivatives are prepared in an extruder by the method of solid-phase synthesis via the interaction of chitosan and 2,2-bis(hydroxymethyl)propionic acid. The effect of the initial component ratio and temperature on the yield and structure of the target products is studied. Joint deformation of solid components at room temperature is found to cause the quantitative formation of salt bonds between carboxylic groups of the acid and amino groups of chitosan. At elevated temperatures of synthesis, the corresponding acetylated derivatives with a degree of substitution of amino groups varying from 0.16 to 0.43 are prepared. The relaxation and phase transitions in the polymer salts and acetylated chitosan derivatives and their sorptional activity are studied. The films prepared from aqueous solutions of the new salt modification of chitosan are characterized by a homogeneous structure and improved mechanical characteristics relative to those of the films based on chitosan acetates. An additional thermal treatment of the products of the solid-phase synthesis leads to the formation of crosslinked and water-swollen materials that can be used for the development of novel polymeric chitosan-based membranes and sorbents. 相似文献