共查询到18条相似文献,搜索用时 63 毫秒
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介绍氨基硫尿路线(ATSC)合成丙酮缩氨基硫脲(ATSC)的反应原理和合成方法;硫氰酸肼路线合成ATSC的反应原理和常压、减压法的合成。重点阐述了减压法的流程和操作过程。指出了硫脲路线和硫氰酸肼路线各自的特点。 相似文献
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含硫席夫碱配体的合成研究——联乙酰双缩氨基硫脲类化合物的合成 总被引:1,自引:1,他引:1
合成了2种含硫脲基席夫碱配体,通过光谱分析确证了其结构,初步试验了它们对部分金属离子的配位性能。 相似文献
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对五种类的含二茂铁基缩氨基硫脲类衍生物的合成方法进行了研究,并对产品进行了分析,与理论值比较接近。 相似文献
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分子筛由于具有规则的孔道结构、适宜的酸性、良好的热和水热稳定性等特点,广泛应用于吸附、分离、离子交换及催化等领域。传统水热法制备分子筛因需要使用大量溶剂和有机模板剂,存在合成效率低、生产成本高、污染环境等一系列问题。近年来,随着"绿色化学"理念的深入人心,开发绿色、可持续的分子筛制备路线备受关注,逐渐成为该领域的研究热点。本文主要从水热法、离子热法、干胶法以及无溶剂法等几个方面,对国内外分子筛绿色合成的最新研究进展进行综述,并归纳比较上述合成方法的优缺点。最后,提出目前绿色合成分子筛过程中存在的问题,展望其未来发展前景。 相似文献
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The results of 1H NMR binding studies of mole-cular tweezers 1a with various aliphatic and aromatic cations in organic solvents are described. By the use of the viologene substrates 11 and 12 bearing bulky endgroups and therefore having a dumb-bell topology it could be demonstrated that besides the obvious mechanism of complexation in which the guest molecule enters the tweezer's cavity through the open sides of the host, a second mechanism is available in which the substrate enters the cavity through a gap emerging after a substantial spreading of the tweezer's tips by at least of about 280 pm. 相似文献
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Glyceride synthesis in a solvent-free system 总被引:6,自引:0,他引:6
Anna Millqvist Fureby Patrick Adlercreutz Bo Mattiasson 《Journal of the American Oil Chemists' Society》1996,73(11):1489-1495
Synthesis of partial glycerides in a solvent-free system has been investigated with various acyl donors and glycerol as substrates
and a 1,3-specific immobilized lipase to catalyze the reaction. Capric acid was the most efficient acyl donor, compared with
ethyl caprate and tricaprin. However, to obtain a high yield of dicaprin and a low amount of tricaprin, ethyl caprate was
the acyl donor of choice. The composition of the product mixture was determined by the ratio of ethyl caprate to glycerol;
a molar ratio of 3∶1 was optimum for dicaprin synthesis. The water content in glycerol did not influence the final yield of
dicaprin, but initial production of capric acid increased with increasing water content. The reaction was found to be controlled
entirely by external mass transfer. The yield of diglyceride could be increased from 70 to 90% by lowering the reaction temperature,
so that the diglyceride precipitated during the reaction. 相似文献
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以蔗糖和脂肪酸甲酯为反应原料,无溶剂条件下采用研磨强化的方法合成了蔗糖脂肪酸酯(即蔗糖酯),考察了研磨时间、乳化剂用量、反应时间、反应压力以及催化剂用量对蔗糖酯收率及脂肪酸甲酯转化率的影响,产品经水洗、醇提精制后,用FTIR和HPLC-ELSD对其进行了表征和分析。结果表明:研磨处理能将反应分散物粒径(D50)降至约5μm,有效地增强了蔗糖与脂肪酸甲酯的无溶剂酯交换反应。得到的最优反应条件为:研磨时间为60min,硬脂酸钾乳化剂质量分数为10%(占体系总质量,下同),K2CO3质量分数为2.0%,反应时间6 h,反应压力0.5 kPa,在该条件下脂肪酸甲酯转化率为91.2%,蔗糖酯收率为61.6%。精制后产品中蔗糖酯质量分数为81.9%,且其游离糖质量分数为0.6%,酸值为3.0mgKOH/g,水分(质量分数)为0.2%和灰分(质量分数)为0.5%,均达到FAO/WHO标准。 相似文献
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综述了近年来以分子筛制备固体碱催化剂的研究进展,包括X型、Y型、L型等微孔分子筛和MCM-41、SBA-15等介孔分子筛经改性得到的固体碱,以及分子筛固体碱催化剂在双键异构化、酯化、酯交换、Knoevenagel缩合、Aldol缩合和Michael加成等有机反应中的应用。 相似文献