Hypocrellin A与二苄胺和N-甲基苄胺的光化学反应

In order to discuss the free radicals formation mechanism of Hypocrellin A（HA）with amino derivatives,the electron-spin resonance（ ESR） spectroscopy was adopted to study the photochemistry on HA with dibenzyl amine（DBA）and N-methyl benzyl amine（NMBA）,respectively. When HA with DBA or NMBA in chloroform solution was illuminated with visible light,singlet oxygen,semiquinone radical and oxynitride radical were formed depending on the condition of the solvent system containing the amino-substituted and solved oxygen. The signal intensity of oxynitride radical decreased with increasing the illumination time,and the signal intensity of semiquinone radical increased with increasing the illumination time. The oxynitride radical content was in inverse ratio with the semiquinone radical generated by being irradiated. In the aerobic system of chloroform solution containing DBA/HA,smiquinone radical was the main radical irradiated. The results indicated that HA induced amino derivatives into HA semiquinone radical.     

聚乙烯苄胺树脂合成条件的研究

利用NICOLET 5DX红外光谱仪研究了聚乙烯苄胺树脂的合成条件和反应历程。结果表明,在适当的条件下采用不同合成方法均可得到聚乙烯苄胺树脂。在某些条件下将引起明显的副反应发生。     

香豆素-3-甲酰苄胺的合成及晶体结构

以香豆素-3-甲酸乙酯(1)为前驱体,与苄胺发生酯的胺解反应,合成了酰胺型香豆素衍生物香豆素-3-甲酰苄胺,通过红外光谱、核磁共振光谱以及X-射线单晶衍射对其进行了结构表征.晶体结构结果表明,每个晶胞中包含2个香豆素-3-甲酰苄胺分子,两个分子之间通过C5-H5···O3和C7-H7···O3氢键相互作用形成环状二聚体...     

希土元素异硫氰酸盐与苄胺配合物的制备、性质及标准生成焓的测定

制备了Pr、Yb两种希土元素异硫氰酸盐与苄胺的固体配合物.并对其进行了组成分析、红外光谱分析、X射线衍射物相分析和热重分析.测量了298.15K时两种固体配合物RE(NCS)₃·4C₆H₅CH₂NH₂在HCl水溶液中的反应热和相应的两种希土元素异硫氰酸盐水合物RE(NCS)₃·n₁H₂O(RE为Pr时,n₁=7;RE为Yb时,n₁=6)在C₆H₅CH₂NH₂-HCl^-H₂O溶液中的积分溶解热以及苄胺C₆H₅CH₂NH₂在HCl水溶液中的反应热.藉助本文所设计的热化学循环,求得了这两种配合物的标准生成焓,还计算了它们的晶格能.     

4-(4-甲基苯氧基)苄胺的合成

甲基苯氧基苄胺;农药;4-(4-甲基苯氧基)苄胺的合成     

WO3/4,4′-联苄胺光致变色超晶格薄膜的研究

无机-有机超晶格薄膜材料的制备以及性质研究是目前国际上的研究热点.基于超分子化学自组装原理,利用自组装技术构建含有有机分子的光致变色纳米超晶格薄膜材料,是一种研制光致变色功能薄膜材料的新方法.此项研究能够为研制变色响应速度快的、稳定性好的、变色可调控的光致变色器件奠定基础,具有深远的意义和重要的科学价值.本文采用溶液中相反电荷聚电解质自组装的方法(PEs法)[1],制备了WO3/4,4′-联苄胺超晶格薄膜;采用紫外可见吸收光谱和小角X-射线衍射谱对薄膜的层状结构和分子的排列方式进行了研究.     

(R)-α-取代苄胺的立体控制合成

通过(+)-樟脑酮亚胺体系的不对称反应已有不少文献报道。近年来,我们曾先后用(+)-樟脑缩甘氨酸特丁酯和(+)-樟脑缩苄胺体系作手性模板,合成了多种生理活性的(R)-α-氨基酸,(R)-α-取代苄胺和β-氨基醇。但产物的光学收率除个别在90％以上外,多数都不高。因此,为寻找具有高的立体选择性的手性模板,我们对天然(+)-樟脑进行结构改造,按Bartlett's方法将樟脑氧化成10-樟脑酸(1),经酰氯化后,在二氯甲烷     

甲氧苄胺嘧啶药物的非破坏分析

将偏最小二乘（ＰＬＳ）法同近红外漫反射光谱法结合，非破坏分析了粉末药品甲氧苄胺嘧啶。讨论了波长对ＰＬＳ定量预报能力的影响。校正样品和预测样品的预测结果相对标准误差分别为０．３３％和１．３９％。     

含苯乙腈母体的酰替芳胺类衍生物的合成

合成了１１种未见文献报道的含苯乙腈母体的新型酰替芳胺类化合物，其结构经ＩＲ、＾１ＨＭＲ、元素等证实，并进行了室内平板杀菌活性试验。     

三丁胺胺化强碱性阴离子交换树脂催化合成羧酸苄酯

用组合化学方法筛选出的对无外加碱条件下的亲核取代催化活性最高的聚合物季铵盐-三丁胺胺化强碱性阴离子交换树脂为相转移催化剂,催化合成了乙酸苄酯、丙酸苄酯、丁酸苄酯、戊酸苄酯等羧酸苄酯。讨论了各种反应条件对合成丙酸苄酯的产率的影响,并对传统合成方法进行了改进。在优化反应条件下,反应产率接近100%。     

Optical Sensing Membrane Based on Tetrabromophenolphthalein Ethyl Ester for the Determination of Cationic Surfactants

Abstract

An optical sensing membrane for detection of cationic surfactants was developed. The optical sensing membrane is 2‐nitrophenyl octyl ether‐plasticized poly(vinyl chloride) membrane incorporating tetrabromophenolphthalein ethyl ester (TBPE). The response of the optical membrane to cationic surfactants was a result of extraction of cationic surfactant into the PVC membrane. The protonated TBPE deprotonates forming an ion associate with the extracted cationic surfactant; simultaneously, the deprotonation of the TBPE is accompanied by a spectral change. Namely, the extracted cationic surfactant changes color of the membrane from yellowish green to blue (absorption maximum: 622 nm). The optical membrane responds to cationic surfactants such as Zephiramine and cetyltrimethylammonium bromide in the concentration range from 1 µM to 100 µM.     

Reversible Optical Sensor Membrane for Hydrogen Peroxide Using an Immobilized Fluorescent Probe,and its Application to a Glucose Biosensor

An optical sensor for hydrogen peroxide (HP) based on the probe europium tetracycline (EuTc) incorporated into a polyacrylonitrile-co-polyacrylamide polymer matrix is described. Upon optical excitation with 400-nm light, the EuTc in the membrane displays fairly strong fluorescence peaking at 616nm. The fluorescence intensity increases up to 3-fold if the sensor is exposed to solutions containing HP. The effect is reversible and can thus be used for continuous sensing. The largest signal changes with HP are observed at pH levels between 6.5 and 7.5, and the range of the response is between 10 and 300ppm (w/w) of HP, equal to 0.3 to 10mmolL^–1). At concentrations above 0.3% of HP, decomposition of the EuTc in the membrane is observed. The limit of detection is 15ppm (0.45mmolL^–1). The response is fully reversible and rather slow (10min) in both directions, but the reverse response may be accelerated by addition of a reducing agent such as thiosulfate. Alkali ions and most anions remain inert, but phosphate and citrate interfere, as do Cu²⁺ ions, which quench fluorescence. In order to image the spatial distribution of HP concentrations, sensor membranes were placed on the bottom of the wells of a microtiter plate, and their fluorescence was imaged using an LED-based device based on the measurement of the luminescence decay time of EuTc. If glucose oxidase is immobilized on the sensor layer, a glucose sensor is obtained in which the HP sensor acts as the transducer and which can quantify glucose in concentrations between 0.1 and 5mmolL^–1. The limit of detection for glucose is 0.2mmolL^–1.     

A Novel Optical Sensor for Determination of Thiocyanate

Abstract

A novel optical sensor (optode) is described for the determination of thiocyanate using methyltrioctylammonium chloride immobilized on triacetylcellulose membrane. The response to thiocyanate is the result of adsorption of [Co(SCN)₄]^2? on sensing membrane, which caused the colorless membrane to change to blue. This optode can readily be regenerated by using 0.02 mol/l sodium oxalate solution. The linear range of the method was 3.44×10^?5 to 8.61×10^?4 mol/l of thiocyanate with a limit of detection 1.51×10^?5 mol/l. The relative standard deviation for eight replicate measurements of 8.61×10^?5 and 4.30×10^?4 mol/l of thiocyanate was 3.45 and 1.23%, respectively. The sensor was successfully applied for the determination of thiocyanate in saliva of smokers, nonsmokers and various water samples.     

Probes and Polymers for Optical Sensing of Oxygen

Oxygen detection techniques are used in various fields, such as chemical or clinical analysis and environmental monitoring. Recently, a variety of devices and sensors based on photo-luminescent or photoexcited state quenching of organic dyes have been developed to measure oxygen partial pressure on the solid surface. Many optical oxygen sensors are composed of organic dyes, such as polycyclic aromatic hydrocarbons (pyrene, pyrene derivative etc.), transition metal complexes (Ru²⁺, Os²⁺, Ir³⁺ etc.), metalloporphyrins (Pt²⁺, Pd²⁺, Zn²⁺ etc.) and fullerene (C₆₀ and C₇₀) immobilized in oxygen permeable polymer films. In this review, the properties of various oxygen permeable polymers for matrix of optical oxygen sensor and various dye probes for oxygen sensing are described.Received November 19, 2002; accepted May 14, 2003 published online August 22, 2003     

纳米氧化锰负载钛基电催化膜制备及其苯甲醇催化氧化性能

利用乳液法制备出MnO_x纳米颗粒,将其负载于微孔管式钛膜制得MnO_x负载钛基电催化膜(MnO_x/Ti).运用X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、循环伏安法(CV)和计时电流法(CA)等表征方法系统考察了不同焙烧温度下MnO_x晶型结构、MnO_x/Ti催化膜电化学性能以及催化氧化苯甲醇的变化规律.结果表明:随着焙烧温度的升高, MnO_x的晶型由初始的Birnessite-MnO₂逐渐转变为K_0.27MnO₂,再由Mn3O4最终转变为α-MnO₂.所得MnO_x/Ti膜中, α-MnO₂晶粒尺寸小于30 nm,结晶度较高,颗粒分布均匀.同时,由于其含有不饱和配位的锰原子和氧空位以及与基体Ti之间存在键合作用,表现出优异的电化学性能和催化性能.以450 ℃焙烧所得的α-MnO₂/Ti为阳极构建电催化膜反应器催化氧化苯甲醇.在反应温度为25 ℃, 50mmol·L^-1苯甲醇水溶液,电流密度为2 mA·cm^-2,停留时间为15 min的条件下,膜反应器苯甲醇转化率达64%,苯甲醛选择性为79%.     

Design of an Optical Sensor for Determination of Bismuth

An optical chemical sensor (optode) for the determination of Bi(III) has been designed by immobilization of methyltrioctylammonium chloride on triacetylcellulose polymer. The exchange of chloride as counter ion with iodide in the membrane changes the colorless film to orange, when it is placed in acidic solution of Bi(III). The sensor can readily be regenerated by 0.1 mol L^‐1 sodium citrate solution in less than 15 s. Under optimum conditions, the proposed membrane is capable of determining Bi(III) over a dynamic range between 3.36 × 10^‐6 and 4.80 × 101^‐5 mol L^‐1 with a limit of detection 1.02 × 10^‐6 mol L^‐1. The relative standard deviation for seven replicate measurements of 9.60 × 10^‐6 and 3.84 × 10^‐5 mol L^‐1 of Bi(III) was 3.79 and 2.14%, respectively. The sensor was successfully applied to the determination of bismuth in tablet and water samples.     

叔铵盐—烷烃—醇—水四元体系的热力学函数与结构研究

叔铵类(R_3N)萃取剂萃取金属离子需在酸性介质中进行,与无机酸先形成铵盐(属阴离子表面活性剂类),然后与金属配阴离子进行阴离子交换反应。而将R_3N制成无机酸盐,作为表面活性剂以微乳液为模型对其进行热力学函数与结构研究尚未见报道。 本文制备了TOA·HCl、N235·HCl、N235·HNO_3与N235·HClO_44种叔铵无机酸盐,测定了叔铵盐的界面化学性质。以w/o型微乳液的球形颗粒结构为模型,用稀释法测定了叔铵盐(TOA·HCl,N235·HCl,N235·HNO_3,N235·HClO_4)-烷烃-醇-水四元均相透明体系的结构参数;并用不同醇时,醇由油相(o)转移至界面层(i)的标准自由能变(?)结果表明其结构“颗粒”半径小于0.5nm,表面活性剂叔铵盐的平均聚集数小于0.05,应属醇的反向胶团。 1 实验 1.1 试剂 三正辛胺(TOA,德国);N235(R_3N,R=C_5—C_(10),大连油脂化学厂)。叔铵盐TOA·HCl分别用干法(D)与湿法(W)制备。向TOA中通入干燥HCl气体至饱和,再加入分析量的TOA中和过量的HCl,制得TOA·HCl(D).TOA与过量10mol/L盐酸振荡平衡,再加入分析量的TOA中和过量酸制得TOA·HCl(W),样品均为淡黄色蜡状固体,N235·HCl、N235·HNO_3、N235·HClO_4均用湿法制备。其它试剂均为A.R.级,未进一步处理,水为二次蒸馏水。     

固定酚红的交联聚乙烯醇光化学pH敏感膜

An optical pH sensitive membrane for optical pH sensors has been developed by covalently immobilizing phenol red on optical transparent cross-linked polyvinyl alcohol （PVA） membrane surfaces. The phenol red was first reacted with acrylamide to form a product of acrylamide grafted phenol red （AAGP）, then the AAGP was covalently immobilized to the PVA membrane via surface grafting-polymerization using Fe^2＋/H2O2 as initiator. The performance of the pH sensitive membrane was investigated and the results showed that the pH sensitive membrane has some features including a linear response scope from pH 6.5 to 8.5 closed with phenol solution, a rapid response time （〈：20 s）, good reproducibility, reversibility, excellent stability and easiness of fabrication. These show that the pH sensitive membrane can be used as a sensitive layer for optical pH sensor.