磺胺胍与四氯苯醌的荷移反应

研究了磺胺胍与四氯苯醌之间的荷移反应。在碳酸钠 碳酸氢钠缓冲溶液中磺胺胍与四氯苯醌能形成淡紫色荷移配合物。配合物的最大吸收波长为540nm,表观摩尔吸光系数为2.45×103L·mol-1·cm-1,线性范围为0～50mg·L-1,其配合比为1∶2。应用拟定的方法测定磺胺胍制剂的含量,平均回收率为99.5%,RSD为0.38%(n=6),可用于实际样品的分析。     

蛋白质—四氯苯醌荷移反应的分光光度研究

本文用分光光度法研究了蛋白质—四氯苯醌荷移反应。通过对影响反应各因素的研究,确立了以四氯苯醌形成荷移络合物的方法测定蛋白质的最佳条件,测定了最大结合数及反应平衡常数。     

尿酸与四氯苯醌的荷移反应及其分析应用

采用紫外分光光度法研究了尿酸与四氯苯醌之间的荷移反应。在乙腈溶液中,尿酸与四氯苯醌可迅速形成稳定的1∶1荷移配合物。其最大吸收波长为450 nm,表观摩尔吸光系数ε=1.52×104L.mol-1.cm-1,线性范围是1.01×10-6~10.1×10-6mol/L。用本法测定人体代谢物中的尿酸,回收率为99.8%~105.6%,相对标准偏差(RSD)为3.48%(n=5)。     

对苯醌与磺胺类药物荷移反应的研究

本文研究了对苯酯与磺胺类药物［磺胺二甲嘧啶（ＳＭ２），磺胺嘧啶（ＳＤ）和磺胺甲基异恶唑（ＳＭＺ）］的荷移反应条件，络合物组成?初步探讨了此荷移反应的动力学性质和反应机理，应用拟定的方法测定了ＳＤ和ＳＭＺ等药物含量。     

分光光度法研究氨基酸与四氯苯醌形成的荷移配合物

本文用分光光度法研究了5种氨基酸与四氯苯醌形成的荷移配合物.通过对影响配合物形成因素的研究,确立了以四氯苯醌形成荷移配合物的方法测定氨基酸的最佳反应条件,测定了反应平衡常数.讨论了配合物的组成.     

利用荷移反应分光光度法测定针剂中的多巴胺

研究了多巴胺与四氯苯醌之间的荷移反应，测量络合物组成比为１：１，摩尔吸光系数ε＝１．６３＊１０＾３。方法的相对标准偏差为１．２％。应用据说 定方法测定物制剂中多巴胺含量与药典方法一致，回收率在９４．５％－１０２％。     

荷移反应用于测定红霉素

1　引　　言红霉素为大环内酯类抗生素。已报道的分析方法有 :抗生素微生物检定法、高效液相色谱法、分光光度法等。本文首次利用其与茜素的荷移反应 ,建立起简便的分光光度法 ,对红霉素片剂中的有效成分进行含量测定 ,测定波长是 5 49ｎｍ ;表观摩尔吸光系数是 3 .5 6× 10 3Ｌ·ｍｏｌ- 1 ·ｃｍ- 1 ;线性范围是 10～ 2 0 0ｍｇ/Ｌ ;回收率在 95 %以上。用本方法和文献方法测定药物制剂中有效成分的含量 ,结果相符。2　实验部分2 1　主要仪器与试剂　 72 1分光光度计 (上海第三分析仪器厂 )。 1 2 5ｇ/Ｌ红霉素 (药物纯 )乙醇溶液 ;4.5×…     

盐酸羟胺与对苯醌荷移反应及盐酸羟胺的测定

盐酸羟胺是工业生产中常用的还原剂,简便、快速地测定工业品盐酸羟胺及其工业生产过程中的含量十分重要。盐酸羟胺的分析方法有多种,包括滴定法、电化学法、分光光度法等。荷移光谱是在光能激发下,某一化合物中的电荷重新分配,导致电荷从化合物的一部分迁移至另一部分而产生的吸收光谱。化合物呈现电荷迁移光谱,其必要条件是化合物的组分之一具有电子给予体的特征,另一组分也应具有电子接收体的特征。盐酸羟胺分子中的胺氮原子有孤对电子成为电子给予体,对苯醌具有兀轨道而作为电子接收体,它们发生荷移反应生成荷移络合物。     

基于荷移反应的高效液相色谱法测定氨基丁醇

建立了一种基于荷移反应的高效液相色谱测定氨基丁醇含量的分析方法。在pH 8.4的硼砂-硼酸缓冲溶液中,氨基丁醇与四氯苯醌于60℃反应60 min,利用高效液相色谱法-紫外检测器进行分析。荷移络合物采用Agilent Extend C18色谱柱（250 mm×4.6 mm,5 μm）分离,以0.001%（体积分数）三乙胺甲醇溶液为流动相进行梯度洗脱,流速为1 mL/min,检测波长为350 nm。该方法对氨基丁醇的定量限为0.01 g/L,线性范围为0.1~0.6 g/L,相关系数（R²）为0.9994;方法的加标回收率为98.3%~103.6%,相对标准偏差（RSD）为0.9%~1.6%。该法简便快捷,适用于氨基丁醇含量的快速检测。     

利用电荷迁移反应测定头孢羟氨苄

提出一种基于电荷迁移反应简便可靠地测定头孢羟氨苄的分光光度法。在甲醇－乙醇介质中，头孢羟氨苄与氯冉酸于５０℃反应１５ｍｉｎ能够形成稳定的１：１络合物，其λｍａｘ＝５２８ｎｍ，线性范围为２０￣４００ｍｇ／Ｌ。用拟定的方法测定原粉和胶囊，结果与药典法一致。对浓度１００ｍｇ／Ｌ的药物１０次测定相对标准偏差为１．４％，样品的标准加入回收率为９９．０％￣１００．８％。     

氧氟沙星的荷移分光光度法测定

研究了氧氟沙星与７，７，８，８－四氰基对二次甲基苯醌（ＴＣＮＱ）的荷移反应，确定了反应的最佳条件，在甲醇－丙醇（３：２）介质中，二者于３０℃水浴中恒温３０ｍｉｎ即可形成１：１络合物，在测定波长７４３ｎｍ处络合物的表观摩尔吸光系数为３．５８×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，氧氟沙星浓度在０～１５ｍｇ／Ｌ范围内符合比尔定律，方法的相对标准差小于３％。     

头孢唑啉钠的荷移分光光度法测定

研究了头孢唑啉钠与７，７，８，８－四氰基对二次甲基苯醌（ＴＣＮＱ）的荷移（ＣＴ）反应，确立了荷移反应的最佳条件。结果表明：在丙酮－甲醇介质中，两者于３０℃水浴中恒温３０ｍｉｎ即可形成１∶２的络合物，在其最大吸收波长７４３ｎｍ处表观摩尔吸光系数ε＝１７６×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，在０～２４ｍｇ／Ｌ范围内符合比尔定律线性关系。方法的相对标准偏差小于３％（ｎ＝１０）。对形成ＣＴ络合物的机理进行了探讨。并应用拟定的方法对样品注射用头孢唑啉钠进行了含量测定，结果与标准方法一致，回收率符合要求     

Charge-transfer interactions in cyclophanes

Charge-transfer interactions in cyclophane systems are reviewed. The majority of the work covered involves intermolecular complexation, with both donor and acceptor moieties existing within the same molecule. Studies have also been performed on intermolecular complexes, mainly tetracyanoethylene:cyclophane complexes. Host-guest complexes involving charge-transfer are also discussed. Other areas covered include solvent effects, substituent effects, and theoretical calculations.     

Charge-transfer excitons in DNA

There have been a number of theoretical treatments of excitons in DNA, most neglecting both the intrachain and interchain wavefunction overlaps of the electron and hole, treating them as Frenkel excitons. Recently, the importance of the intrachain and interchain coupling has been highlighted. Experiments have shown that in (dA)n oligomers and in duplex (dA)n.(dT)n, to be abbreviated (A/T), where A is adenine and T is thymine, the exciton wavefunction is delocalized over several bases. In duplexes it is possible to have charge-transfer (CT) excitons. Theoretical calculations have suggested that CT excitons in DNA may have lower energy than single chain excitons. In all the calculations of excitons in DNA, the polarization of the surrounding water has been neglected. Calculations have shown, however, that polarization of the water by an excess electron or a hole in DNA lowers its energy by approximately 1/2 eV, causing it to become a polaron. It is therefore to be expected that polarization charge induced in the surrounding water has a significant effect on the properties of the exciton. In what follows, we present calculations of some properties CT excitons would have in an A/T duplex taking into account the wavefunction overlaps, the effect of the surrounding water, which results in the electron and hole becoming polarons, and the ions in the water. As expected, the CT exciton has lowest energy when the electron and hole polarons are directly opposite each other. By appropriate choice of the dielectric constant, we can obtain a CT exciton delocalized over the number of sites found in photoinduced absorption experiments. The absorption threshold that we then calculate for CT exciton creation in A/T is in reasonable agreement with the lowest singlet absorption deduced from available data.     

Reaction of Dimethyl Acetylene-Dicarobxylate With Triazinone

Abstract

The addition of dimethyl acetylenedicarboxylate (DMAD) to 6-menthy-1, 2,4-triazlne-3(2H)thione-5(4H)-one afforded 2-methoxylcarboxy-7-methyl-1,3-thiazino[3,2-b][1,2,4]triazine-4,8-dione.     

Charge-transfer polymerization of butyl methacrylate

Butyl methacrylate (BuMA) can be polymerized by charge-transfer complexes formed by the interaction of ethanolamine (EA), BuMA, and carbon tetrachloride (CCl₄) in a non-aqueous solvent, such as N,N-dimethylformamide (DMF) or dimethyl sulfoxide (DMSO). The rate of polymerizationR _p is found to be linear with [BuMA] and proportional to both [CCl₄]^0.5 and [EA]^0.5 when [CCl₄]/[EA]≤1.R _p becomes independent of [CCl₄] when [CCl₄]/[EA]>1.R _p is proportional to [EA]^0.56 and to [BuMA]^1.30 when [CCl₄]>[EA]. The average rate constant at 30°C for the polymerization of BuMA in terms of monomer was 3.32×10⁻⁶ s⁻¹ when [CCl₄]/[EA]≤1, and 5.47×10⁻⁶ L/(mol s) when [CCl₄]/[EA]>1.