光谱法研究水团簇结构对AlCl3溶液与血清白蛋白作用的影响

研究了冷冻-解冻处理对A1CI₃溶液团簇结构和AICl₃与血清白蛋白相互作用的影响。测定了AICl₃溶液冷冻-解冻处理前后电导率的变化,发现AICI₃溶液经冷冻处理后,电导率有明显增加。采用紫外分光光度法和荧光光谱法对冷冻前后AICI₃溶液与血清白蛋白相互作用的研究表明,A1C1₃溶液经冷冻-解冻处理后,与血清白蛋白的相互作用变弱,配位诱导作用降低,静态猝灭作用变小,这种相互作用变弱的效应是由于水的分子团簇结构变化引起的。     

茶叶中总黄酮含量测定方法的研究

茶叶中富含羟基苯甲酸类、肉桂酸类及原花色素等多酚类物质,这些物质都具有邻苯二羟基结构,碱性环境下与铝离子形成络合物,影响总黄酮的测定。本实验用亚硝酸钠-硝酸铝法和三氯化铝法测定茶叶总黄酮含量的结果作了比较。实验结果表明,亚硝酸钠-硝酸铝法的测定结果比三氯化铝法约高60mg/g,三氯化铝法在酸性环境下进行,酸度实验显示,适宜酸度为pH≥5.0。鞣酸干扰实验表明,平均误差为0.017mg,随着鞣酸量的增加,测得值无上升趋势。三氯化铝法的线性方程:y=0.000638 0.8623x,相关系数:r=0.9998;样品加标回收率为98.05%。因此,对含酚类较多的植物应采用三氯化铝法测定其总黄酮的含量。     

用高效液相色谱法优化苯与对氯氯苄烷基化反应催化剂

用高效液相色谱法优化苯与对氯氯苄烷基化反应催化剂刘红霞张书胜袁倬斌＊（郑州大学分析测试中心郑州）（中国科学技术大学研究生院北京１０００３９）关键词氯－二苯甲烷，制备，三氯化铝，硝基苯，硝基乙烷，高效液相色谱法１９９７－０３－３１收稿，１９９７－０９－...     

高活性固载化三氯化铝催化合成金刚烷

首次用固载化AlCl3催化剂催化桥式四氢双环戊二烯异构化反应合成金刚烷.结果表明,以γ-Al2O3为载体的固载化AlCl3催化剂在较低的反应温度(140℃)下具有较高的催化活性和生成金刚烷的选择性,桥式四氢双环戊二烯的转化率达到100%,金刚烷的选择性为17.7%;而以Si O2作为载体制备的催化剂,几乎没有金刚烷生成.     

无水三氯化铝催化乙醇脱水反应制乙烯的实验研究

针对浓硫酸或五氧化二磷作催化剂的不足,该研究采用无水三氯化铝催化乙醇制乙烯,可使反应体系在120~130℃左右产生大量乙烯气体。同时从理论上探究了无水三氯化铝催化乙醇脱水的机理,并从教学演示实验的角度改进了反应装置,取得了较好的实验效果。     

EPR and DFT Study of the Polycyclic Aromatic Radical Cations from Friedel-Crafts Alkylation Reactions

Electron paramagnetic resonance and electron-nuclear double resonance methods were used to study the polycyclic aromatic radical cations produced in a Friedel-Crafts alkylating sys- tem, with m-xylene, or p-xylene and alkyl chloride. The results indicate that the observed electron paramagnetic resonance spectra are due to polycyclic aromatic radicals formed from the parent hydrocarbons. It is suggested that benzyl halides produced in the Friedel-Crafts alkylation reactions undergo Scholl self-condensation to give polycyclic aromatic hydrocar- bons, which are converted into corresponding polycyclic aromatic radical cations in the presence of AlCl3. The identification of observed two radicals 2,6-dimethylanthracene and 1,4,5,8-tetramethylanthraeene were supported by density functional theory calculations using the B3LYP/6-31G（d,p）//B3LYP/6-31G（d） approach. The theoretical coupling constants support the experimental assignment of the observed radicals.     

三氯化铝催化合成环己酮异Vc缩酮

研究了常用催化剂对合成环己酮异Vc缩酮(3)的影响,结果表明,AlCl3的催化活性最佳.最佳反应条件为:环己酮20 mmol,n(环己酮):n(异Vc)=1.0:1.6,AlCl3 1 mmol,DMAc 12 mL,环己烷10 mL(带水剂),于120℃反应2.5 h,3的收率达86.48%.     

Monitoring the reaction between AICl3 and o-xylene by using terahertz spectroscopy

Terahertz time-domain spectroscopy （THz-TDS） is used to study the interaction between AlCl3 and o-xylene in a temperature range from 300 K to 368 K. For comparison, the three isomers of o-, m-, and p-xylene are measured by using THz-TDS. The o-xylene carries out isomerization reaction in the presence of catalyst AlCl3. The absorption coefficient of the mixed reaction solution is extracted and analyzed in the frequency range from 0.2 THz to 1.4 THz. The temperature dependence of the absorption coefficient, which is influenced by both the dissolution of AlCl3 and the production of the two other isomer resultants, is obtained, and it can indicate the process of the isomerization reaction. The results suggest that THz spectroscopy can be used to monitor the isomerization reaction and other reactions in chemical synthesis, petrochemical and biomedical fields.     

4-对甲苯基-4-氧代丁酸的制备——推荐一个大学基础有机化学实验

介绍一个利用Friedel Crafts反应制备γ芳基取代的γ羰基酸———4对甲苯基4氧代丁酸的方法。该实验以甲苯和丁二酸酐为原料,在无水三氯化铝催化下通过付氏酰基化反应,经加热、酸化水解、水蒸气蒸馏,最后得固体产品。推荐该实验作为大学有机化学基础实验。     

Sm/AlCl3·6H2O体系促进的叠氮化合物的化学选择性还原:一种制备胺的新方法

在金属钐和六水合三氯化铝的存在下,叠氮化合物能在温和及中性条件下高产率地被还原为相应的胺.