锑(Ⅲ)-2-(3,5-二溴-2-吡啶偶氮)-5-二乙胺基酚-溴代十六烷基三甲胺的络合物吸附波

在pH5.3的HAc－NaAc、2－（3，5－二溴－2－吡啶偶氮）－5－二乙氨基酚（3，5－Br2－PADAP）、溴代十六烷基三甲铵（CTMAB）溶液中，用线性扫描示波极谱法可得到锑（Ⅲ）的络合物吸附波。峰电位为－0.70V（vs．SCE）。二阶导数档峰高与Sb（Ⅲ）浓度在3．3X10-8～2．5X10－6mol／L范围内呈线性关系。检出限为8．2X10-9mol／L。用多种电化学方法研究了极谱波的性质及电极反应机理。络合物组成为Sb（Ⅲ）：3，5－Br2－PADAP＝1∶2。加入CTMAB可消除试剂峰且提高灵敏度。试验了30多种离子对峰电流的影响，用流基棉分离干扰离子。方法已用于矿样中锑的测定。     

二次微分简易示波伏安法用于胃舒平片剂中铝的测定

向3.75×10 -5mol/LCd2 + -4.0×10 -5mol/L芦丁 -0.05mol/LKNO3-0.05mol/LNa2B4O7 中加入Al3 +时 ,二次微分简易示波伏安图上由Cd -芦丁配合物产生的峰高在一定范围内随Al3 + 浓度的增加线性降低 ,据此建立了测定Al3 +的二次微分简易示波伏安法 ;线性范围为1.0×10 -6～6.5×10 -4mol/L ,检出限为6.0×10-7 mol/L ;该法用于胃舒平片剂中铝的测定的相对标准偏差为3.3 %(n=5)。     

钙-茜素红S的示波行为及应用

在0.1 mol/L KOH底液中,研究了Ca2+与ARS形成络合物的示波行为,并根据其在dE/dt-E曲线阴极支-0.83V产生一灵敏切口的示波特性建立了测定葡萄糖酸钙口服液及片剂中钙含量的二次微分简易示波伏安法。当Ca2+浓度在4.0×10-7～1.9×10-5mol/L时.二次微分简易示波伏安图上Ca-ARS的峰高与Ca2+浓度呈线性关系:相关系数为0.9973;检出限为3×10-7mol/L。对2.0×10-6mol/L Ca2+6次测定的RSD为1.2％.     

苯巴比妥的二次微分简易示波伏安法测定

利用苯巴比妥的示波特性 ,分别建立了在0.2mol/LKOH和1.0×10-4mol/LCd2 +-0.1mol/L硼砂底液中直接和间接测定苯巴比妥的二次微分简易示波伏安法 ;直接测定和间接测定的线性范围分别为1.0×10 -5mol/L～1.0×10 -4mol/L和4.0×10 -6mol/L～8.0×10 -5mol/L ;检出限分别为8×10 -6mol/L和2×10 -6mol/L;在直接测定中 ,对6.000×10 -5mol/L苯巴比妥进行10次测定的RSD为4.5 % ;间接测定中 ,对2.000×10 -5mol/L苯巴比妥进行10次测定的RSD为2.6 % ;这一研究表明对于一些在示波分析中灵敏度不高或本身没有示波活性的药物 ,可以利用其与金属离子生成沉淀的方法间接测定 ,从而提高药物测定的灵敏度、拓宽示波分析应用领域     

用脉冲波交流电流作为极化电流的微分简易示波伏安法

用脉冲波交流电流作为极化电流的微分简易示波伏安法郑建斌，赵明仁，朱小红，苏玉祥（西北大学化学系电分析化学研究所，西安，７１００６９）关键词示波分析，微分简易示波伏安法，脉冲波交流电流经典示波计时电位法在微量乃至于痕量组分的直接测定方面的应用一直进展缓...     

β-环糊精用于L-苯丙氨酸的二次微分简易示波伏安测定

在0.2 mol.L-1NaOH底液中,β-环糊精在二次微分简易示波伏安图上-0.38 V处产生一可逆峰,阴极支的峰高随L-苯丙氨酸与β-环糊精形成的包结物量的增加而降低。根据β-环糊精的示波特性,建立了L-苯丙氨酸含量测定的二次微分简易示波伏安法。试验结果表明:β-环糊精在二次微分简易示波伏安图上的峰高与L-苯丙氨酸浓度在2.5×10-6~4.5×10-5mol.L-1范围内呈线性关系,相关系数为0.999 6,检出限为1.0×10-6mol.L-1。对于8.0×10-5mol.L-1L-苯丙氨酸5次测定的RSD为3.1%,平均回收率为100.0%。测得β-环糊精与L-苯丙氨酸形成包结物的包结比为1∶1,包结常数为1.9×106。     

多贝斯的电化学行为及其测定

研究了多贝斯在汞电极上的示波行为,在玻碳电极上的线性扫描伏安行为和循环伏安行为,建立了胶囊中多贝斯含量的微分脉冲伏安测定法。在汞电极的示波计时电位图上,多贝斯能在0.2mol LNaOH溶液中产生一对可逆切口,而在0.1mol LH2SO4中仅在阴极支产生一个切口;在玻碳电极上,在0.1mol LH2SO4中被氧化成2 磺基 1,4 苯醌,并在 0.26V产生一氧化峰,在微分脉冲伏安图上峰高与浓度在2.20×10-8～3.40×10-6mol L范围内呈线性关系,回归方程为ip(μA)=0.0221 0.0435c(×10-8mol L),r为0.998;检出限为1 1×10-8mol L;对1.50×10-7mol L多贝斯10次测定的RSD为0.96%。     

葡萄酒中白藜芦醇的二次微分简易示波伏安法测定

在 0.2 mol/L KOH介质中 ,用二次微分简易示波伏安法测定了葡萄酒中的白藜芦醇含量。校正曲线的线性范围为 2× 10－ 6～ 5× 10－ 5 mol/L,检出限为 1× 10－ 6 mol/L。对 2.5× 10－ 5 mol/L白藜芦醇测定的相对标准偏差为 1.9％（ n=6）。与其它技术相比较,该法具有仪器简单、操作简便、分析速度快的优点。     

二次微分简易示波伏安法测定痕量镍

用二次微分简易示波伏安法测定了金刚石酸洗废液中的痕量镍 .结果表明 :在 0 .2 0mol/ L NH4 Ac- 0 .0 0 5mol/ L KNO3- 0 .0 2 %丁二酮肟中 ,Ni2 浓度在 3× 10 -7～ 3.5× 10 -6mol/ L范围内与峰高呈线性关系 ,回归方程为 Y=0 .3583 1.365× 10 5c( Ni2 ) ( mol/ L) ,相关系数 r=0 .9970 ,检测下限为 6× 10 -8mol/ L.该法简单、快速、灵敏     

片剂中红霉素的二次微分简易示波伏安法测定

根据在 pH=10.0的NaOH -H3BO3-KCl支持电解质溶液中 ,红霉素在二次微分简易示波伏安图阴极支 -1.55V(vsSCE)处产生一灵敏峰的示波特性 ,建立了测定药品中红霉素含量的二次微分简易示波伏安法 ;校正曲线的线性范围为2.5×10-6～4.8×10-5 mol/L,相关系数为0.9994 ,检出限为1.2×10-6 mol/L;对8.000×10 -6mol/L红霉素进行7次测定的RSD为1.9 % ,样品的平均回收率为99 % ;该法的特点为仪器简单、简便快速、无需通氮除氧。     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

关于"对‘燃料电池物理及化学性能的有限时间热力学分析方法'的讨论”答复

把有限时间热力学理论用于化学过程的研究,将会得到一系列新的结论,开展这方面的研究是很有意义的.文献[1]以燃料电池为例,在同时考虑化学反应及传热不可逆性的情况下,研究了燃料电池的性能界限,文献[2]指出了文献[1]计算化学反应及传热不可逆性而引起系统与有关环境的总熵产生率的错误以及由此而导致的结论所存在的问题,并进行了富有启发性的分析与讨论.但文献[2]对于系统与有关环境的总熵产生率的计算也是不正确的,由此得到的其它结论自然不能成立.本文将就此情况下系统与有关环境的总熵产生率的计算再次进行讨论,并给出电池功率和效率的有限时间热力学性能界限.     

Regiospecific synthesis of quercetin O-β-d-glucosylated and O-β-d-glucuronidated isomers

Quercetin, the polyphenolic compound, which has the highest daily intake, is well known for its protective effects against aging diseases and has received a lot of attention for this reason. Both quercetin 3-O-β-d-glucuronide and quercetin 3′-O-β-d-glucuronide are human metabolites, which, together with their regioisomers, are required for biological as well as physical chemistry studies. We present here a novel synthetic route based on the sequential and selective protections of the hydroxyl functions of quercetin allowing selective glycosylation, followed by TEMPO-mediated oxidation to the glucuronide. This methodology enabled us to synthesize the five O-β-d-glucosides and four O-β-d-glucuronides of quercetin, including the major human metabolite, quercetin 3-O-β-d-glucuronide.     

Cl+F2→ClF+F和F+ClF′→ClF+F′反应机理的密度泛函理论研究

用密度泛函理论(DFT)B3LYP方法, 在6-311G基组下,计算研究了反应Cl+F2→ClF+F和对称反应F+ClF′→ClF+F′的机理。求得前者的过渡态为三角形,活化能为15.57 kJ*mol-1;后者的过渡态为线形和三角形,活化能分别为11.52和196.25 kJ*mol-1。结果均经过振动分析和IRC计算验证。     

丙三醇浓溶液玻璃化转变与结构松弛参数DSC分析

In order to examine the effects of water contents and heating/cooling rates on the glass transition and the structure relaxation parameters of glycerol/water mixtures, five aqueous solutions (60%, 70%, 80%, 90% and 100%) were investigated using the differential scanning calorimetry. Four scanning rates (10, 15, 20, 25 K/min) were used to obtain the glass transition parameters. The fitting results of plasticization constants indicated that Gordon-Taylor relationship could not be used effectively without considering scanning rates and that point on calorimetric step was chosen as the glass transition temperature. The specific heat changes during glass transition processes were relative not only to water content but also to heating rates. With the increasing of water contents in glycerol aqueous solutions, the structure relaxation activation energies and dynamic fragilities were decreased. Since the thermodynamic fragilities were increased with the increasing of water content, so the dynamic fragility and thermodynamic fragility were changed inversely if the water contents were changed in glycerol/water mixtures.     

Deuterodehalogenation—a mild method for synthesising deuterated heterocycles

We report a mild and efficient method for introducing deuterium into a range of heterocycles by reacting readily available halide analogues in a deuterodehalogenation reaction using D₈-IPA or Et₃SiD under palladium-catalysed conditions.     

The conversion of 2-cyano cyanothioformanilides into 3-aminoindole-2-carbonitriles using triphenylphosphine

2-Cyano cyanothioformanilide 3a reacts with triphenylphosphine in the presence of water to give 2-(cyanomethyleneamino)benzonitrile 4a, 2-(cyanomethylamino)benzonitrile 5, 3-aminoindole-2-carbonitrile 2a and (2-cyanoindol-3-yl)iminotriphenylphosphorane 6a. In the presence of p-toluenesulfonic acid in MeOH the reaction between 2-cyano cyanothioformanilide 3a and triphenylphosphine (2 equiv) gives 3-aminoindole-2-carbonitrile 2a in 90% yield. Under the same conditions 2-(cyanomethyleneamino)benzonitrile 4a gives anthranilonitrile 8a, 3-aminoindole-2-carbonitrile 2a and N-(2-cyanophenyl)formamide 9. In addition, substituted 2-cyano cyanothioformanilides 3b-f react with triphenylphosphine and p-toluenesulfonic acid in MeOH to give 3-aminoindole-2-carbonitriles 2b-f in 63-75% yields. Under analogous conditions 2-cyano-4,5-dimethoxyphenyl cyanothioformanilide 2g gives only 4,5-dimethoxyanthranilonitrile 8g and 4,6,7-trimethoxyquinazoline-2-carbonitrile 14g, but in refluxing dry PhMe in the absence of p-toluenesulfonic acid 2-cyano-4,5-dimethoxyphenyl cyanothioformanilide 3g, (2-cyano-5,6-dimethoxyindol-3-yl)iminotriphenylphosphorane 6g and 2-(cyanomethyleneamino)-4,5-dimethoxybenzonitrile 4g are obtained. The structure of 2-(cyanomethyleneamino)-4,5-dimethoxybenzonitrile 4g is supported unambiguously via independent synthesis and comparison to the isomeric 6,7-dimethoxyquinazoline-2-carbonitrile 15. All new compounds are fully characterised and a tentative mechanism for the transformation of 2-cyano cyanothioformanilides to indoles is proposed.