饱和漆酚冠醚PVC膜钾离子选择电极的研制

目前,钾离子选择电极一般采用缬氨酶素^[1~3]、4,4'-二甲基二苯并-30-冠醚-10^[4]和4,4'-二叔丁基二苯并-30-冠醚-10^[5,6],等作为传感膜的活性物质.其PVC膜电极的线性响应范围为1×10^-5～1×10^-1M氯化钾,对钠离子的电位选择性系数分别为2×10^-4,3.9×10^-3和3.0×10^-3。我们以来源广泛的天然漆酚为原料,经加氢饱和后与二氯醚合成带有长链烷基(正十五烷基)取代的冠醚,简称饱和漆酚冠醚.这种长链烷基的取代将增大冠醚的脂溶性,有利于在PVC膜中均匀分布.其中以饱和漆酚30-冠醚-10的性能较好,适宜于作钾电极.     

氮杂冠醚研究III.N-取代苯并氮杂冠醚的质谱研究

本文报道两种单取代苯并氮杂冠醚(1)和四种双取代苯并氮杂冠醚(2)的电子轰击(EI)质谱及其分子离子峰.化合物(1)的特征峰;m/z 372, 342, 236, 192,136,121, 109, 56;化合物(2)的特征峰:m/z[M-09]^[+],[M/2]^[+],[M/2±13]^[+]等.据此提出了单取代和双取代苯并氮杂冠醚经电子轰击断裂的可能途径.     

钾离子敏感半导体器件的研制

离子敏感半导体器件发展很快,已成为离子选择性电极的一个重要分支。我们用Al_2O_3膜作绝缘栅,并以二苯并-18-冠醚-6(1)和二叔丁基苯并-30-冠醚-10(2)为活性物质制成两种敏感器件。对这两种敏感器件的特性进行测试,其线性响应范围均为1×10~(-4)～1M氯化钾,响应斜率均为55mV/pK,但对钠离子的电位选择性系数分别为1.5×10~(-2)和3.16×10~(-3)。选用Ag-AgCl电极为参比电极与敏感器件封装在一起,这样就充分发挥了敏感器件体积小和牢固的特点。     

N-酰基取代苯并氮杂冠醚~1H和~(13)CNMR谱分析

冠醚化合物以其特殊的配合选择性受到化学工作者的重视,其结构与性能的研究已广泛引起人们的兴趣。本文对新合成的七种冠醚化合物测定了~1H和~(13)C NMR谱,并利用文献值和本组化合物的系列性对谱线进行了归属和讨论。实验部分七种冠醚化合物均由武汉大学化学系合成,其结构式见表1。样品在5mm样品管中以0.5ml CDCI_3(北京化工厂产品)为溶剂配成浓度约为0.5M的溶液。用美国Varian公司XL-200谱仪记谱。探头温度20.0±0.1℃,样品管旋转速度25±5Hz,以氘代氯仿为内锁场信号。     

溴化稀土冠醚配合物LnBr3(18-C-6)·nH2O的振动光谱与结构

本文合成了溴化稀土冠醚配合物, 测定了3500—100 cm~(-1)的付里叶红外和激光喇曼光谱, 并由振动光谱推断LnBr_3(18-C-6)·nH_2O的可能分子结构。     

溴化稀土冠醚配合物LnBr_3(18-C-6)·nH_2O的振动光谱与结构

本文合成了溴化稀土冠醚配合物,测定了3500—100cm~(-1)的付里叶红外和激光喇曼光谱,并由振动光谱推断LnBr_3(18-C-6)·nH_2O的可能分子结构。     

冠醚存在下稀土络合物荧光体系的荧光增强效应

本详细研究了冠醚对Ｅｕ－ＴＴＡ荧光体系的增敏作用和稀土离子Ｄｙ＾３＾＋或Ｈｏ＾３＾＋对Ｅｕ－ＴＴＡ－冠醚体系的荧光强增效应。对Ｅｕ－ＴＴＡ－冠醚和Ｅｕ－Ｄｙ（或Ｈｏ）－ＴＴＡ－冠醚体系，Ｅｕ的浓度分别在１．０×１０＾－＾８－４．０×１０＾－＾６ｍｏｌ／Ｌ，１．０×１０＾－＾９－１．０×１０＾－＾７ｍｏｌ／Ｌ和１．０×１０＾－＾８－９．０×１０＾－＾６ｍｏｌ／Ｌ范围内与体系的荧光强度呈线性关系，检     

铁系元素冠醚配合物的研究——Ⅸ.铁系氯化物与4′-溴-5′-硝基苯并-15-冠-5固体配合物的合成及性质

近年来,有关过渡金属离子冠醚配合物的研究虽有一些报道,但这些研究所涉及的配体大多数是单取代苯并冠醚,对双取代苯并冠醚配位的研究则很少^[1].为了进一步弄清取代冠醚对过渡金属配位性能的影响,我们研究了混合双取代的苯并-15-冠-5,根据文献[2,3]合成了4′-溴-5′-硝基苯并-15-冠-5,并制得了一种新的配合物FeCl₃·L,经性质证明此配合物是1:1型非溶剂合、不含水的固体配合物,其三个Cl^-离子位丁配合物的外界.     

稀土冠醚类配合物的研究——Ⅶ.二价及三价铕氯化物与二环己基-24-冠-8和二价及三价钐、镱氯化物与18-冠-6固体配合物的合成及性质

在THF介质中合成了2:1型固体配合物2EuCl_3·DCH-24-c-8·2THF·2H_2O和4:3型团体配合物4SmCl_3·3(18-c-6)·4H_2O及4YbCl_3·3(18-c-6)·4H_2O。在氩气氛中用锂-萘使Ln~(3+)还原,制得了三种相应的二价稀土氯化物与DCH-24-c-8和18-c-6的固体配合物2EuCl_2·DCH-24-c-8·2H_2O、4SmCl_2·3(18-c-6)·4H_2O及4YbCl_2·3(18-c-6)·4H_2O。元素分析、红外光谱、电子自旋共振谱、差热-热重分析、还原性实验及偏光显微镜下的光性研究不但证实了冠醚与稀土离子的配位作用,而且说明Ln~(2+)及Ln~(3+)的冠醚配合物在物理及化学性质上存在着差别。     

冠醚修饰的C_(60)吡咯烷衍生物的电子结构和性能

利用AM1方法研究了新型C60 衍生物冠醚C60 吡咯烷 (CFP)的电子结构和性能 .全优化发现CFP具有 4种稳定的异构体 ,其构型中苯环平面与吡咯烷平面的夹角约为± 90° .电子结构研究表明 ,CFP的前线轨道主要由C60 部分决定 ,C60 部分是受电子体 ,而冠醚部分为给电子体 ,存在分子内电荷转移现象 .非线性光学性质的研究表明 ,该分子的二阶非线性光学系数的大小与对硝基苯胺相当 ,且随分子构型的不同有较大变化     

A New Application of McReynolds Constants to the Characterization of the Chromatographic Properties of Stationary Phases

An algorithm was proposed for comparing the McReynolds constants of new gas-chromatographic stationary phases with data for not only well-known individual substances but also their binary combinations. It was found that, in most cases, sets of these parameters for the chromatographic properties of new stationary phases are inconsistent with the data for a restricted set of previously characterized phases; however, they are consistent with the properties of phase combinations. This can be interpreted in terms of the absence of specific properties. Exceptions were found only among stationary phases bearing some specific molecular fragments (such as nitro groups) and individual crown ethers.     

Macrocycles as components of gas-chromatographic phases

The use of crown compounds (18-crown-6, benzo-18-crown-6, dibenzo-18-crown-6, benzo-15-crown-5, dibenzo-24-crown-8, 4,13-diaza-18-crown-6,4,13-dibenzyl-diaza-18-crown-6, and cryptand [2.2.2]) as components of stationary phases in the determination of organic compounds by gas chromatography is studied. The polarity, selectivity, efficiency, and working temperature ranges of stationary phases based on crown ethers and cryptand as well as conventional stationary phases for gas chromatography are compared. The influence of the type and number of heteroatoms, the conformational lability of the cavity, and the presence of substituents on the polarity and selectivity of the stationary phases under study is revealed. Preferable types of interactions of stationary phases containing crown compounds with organic compounds of different classes are discussed. It is concluded that phases of the mixed type based on crown ethers are promising for improving the selectivity and efficiency of gas-chromatographic separation     

The gas-liquid chromatographic stationary phase properties of liquid organic salts: Anomalous selectivity variation when employing the Rohrschneider/McReynolds system

The liquid organic salts studied here have wide stable liquid temperature ranges and act as efficient, highly selective gas-liquid chromatographic stationary phases. The effect of carbon number on the gas liquid chromatographic stationary phase properties of this series of tetra-n-butylammonium n-alkylsulfonate salts was evaluated by the well-known Rohrschneider/McReynolds system. Several problems arose when attempting to characterize these polar liquid organic salts employing this system. The specific retention volumes for the polar selectivity probes were generally not affected by an increase in the carbon number for the series studied here. However, the specific retention volumes for the n-alkane retention index markers increased dramatically as the anion carbon number was increased. The overall effect was a net decrease in the calculated McReynolds constants with increasing carbon number, although the true selectivity of the different stationary phases remained constant. Additionally, the specific retention volumes of the basic test probe, pyridine, showed large erratic variations and, in some cases, was not recovered from the columns. The results suggest the possibility of on-column chemical reactions occurring with some of these salts, and an alternative test probe, 2,6-dimethylpyridine (lutidine) is proposed to eliminate this problem. As McReynolds constants are presently the most commonly used parameters for predicting retention and gas chromatographic stationary phase selection, it is important that workers are aware of the inherent limitations of this scheme.     

Comments on column characterization: A sulfur column

Summary The McReynolds' constants for liquid sulfur as a stationary phase in gas-liquid chromatography (GLC) are presented. A simple graphical method of pattern analysis is used to indicate the uniqueness of the sulfur column as compared with other stationary liquid phases characterized by McReynolds. The limitations of using a single factor (as polarity) for the basis for the selection of GLC columns is discussed.     

Preparation of two new liquid chromatographic chiral stationary phases based on diastereomeric chiral crown ethers incorporating two different chiral units and their applications

Two new liquid chromatographic chiral stationary phases based on diastereomeric chiral crown ethers incorporating two different chiral units such as optically active 3,3'-diphenyl-1,1'-binaphthyl and tartaric acid unit were prepared. Between the two CSPs, one was much superior to the other especially in the resolution of tocainide and its analogues (for example, in the resolution of tocainide the separation factor, alpha, was 4.26 vs. 1.00 on the two CSPs). From these results, the two chiral units composing the two diastereomeric chiral crown ether moieties of the stationary phases were expected to show "matched" or "mismatched" effect on the chiral recognition according to their stereochemistry. The different chiral recognition abilities of the two CSPs were rationalized by the different three-dimensional structures of the two diastereomeric chiral crown ethers.     

Prediction of retention data from stationary phase constants in gas chromatography

Summary Specific retention volumes and retention indices for selected compounds can be predicted from different sets of stationary phase constants by multiple regression. Errors in the corresponding calculated retention times are between 5 and 15%. Intercept (A) and slope (B) values are given for 72 McReynolds stationary phases. The A value can be predicted from the retention index of benzene with a standard deviation of 9%.     

Quantitative evaluation of interactions of organic compounds with 18-crown ethers and β-cyclodextrin as components of stationary phases for gas chromatography

Individual stationary phases for gas chromatography based on 18-crown-6 and dibenzo-18-crown-6 (10% on Inerton N AW) and a stationary phase of a mixed composition (polyethylene glycol PEG-3000 and cyclodextrin β-CD) are prepared. These stationary phases are characterized using the McReynolds system and the Abraham solvation parameter model. It is shown that the solvation parameter model can be used to estimate the polarity of gas-chromatographic stationary phases based on the differences in intermolecular interactions between the studied gas-chromatographic stationary phase and the analyte during the separation process. Binary gas-chromatographic stationary phases based on glycerin and β-cyclodextrin with different concentrations of the macrocycle are studied at temperatures of 60 and 80°C, and the complexation constants of β-cyclodextrin with organic substances of various classes are calculated.     

Novel stationary phases based on asphaltenes for gas chromatography

We present the results of investigations on the possibility of the application of the asphaltene fraction isolated from the oxidized residue from vacuum distillation of crude oil as a stationary phase for gas chromatography. The results of the investigation revealed that the asphaltene stationary phases can find use for the separation of a wide range of volatile organic compounds. The experimental values of Rohrschneider/McReynolds constants characterize the asphaltenes as stationary phases of medium polarity and selectivity similar to commercially available phases based on alkyl phthalates. Isolation of asphaltenes from the material obtained under controlled process conditions allows the production of a stationary phase having reproducible sorption properties and chromatographic columns having the same selectivity. Unique selectivity and high thermal stability make asphaltenes attractive as a material for stationary phases for gas chromatography. A low production cost from a readily available raw material (oxidized petroleum bitumens) is an important economic factor in case of application of the asphaltene stationary phases for preparative and process separations.     

Austauscher mit cyclischen Polyethern als Ankergruppen—I: Herstellung und Charakterisierung

Numerous exchangers with cyclic polyethers as anchor groups have been prepared and their properties examined. 4-Carboxyethyl- and 4-hydroxypropylbenzo crown ethers were fixed to silica gel and used as stationary phases in high-pressure liquid-chromatography.