新型酯型反相高效液相色谱填料的制备,表征及性能评价

将一种新型硅烷偶联剂β－（3，4－环氧环己基）乙基三甲氧基硅烷（β－ECTS）与辛酸反应，然后再键合到硅胶上，得到了酯型键合固定相。用元素分析，^13C固体核磁共振谱，红外光谱进行了表征。以甲醇和水为二元流动相，用包括碱性，酸性和中性有机化合物在内的混合物评价该固定相的疏水性，选择性和亲碱醇基效应，并考察了该填料适用的pH范围及水解稳定性，结果表明，该固定相具有较好的色谱性能，且在pH=2.5-7.5之间稳定性良好，可有效地用于碱性化合物的分析分离。     

胺型键合反相固定相的制备及评价

首次将一种新型硅烷偶联剂--β-（3，4-环氧环已基）乙基三甲氧基硅烷（β-ECTS）与辛胺反应，然后再键合到硅胶上，得到了胺型键合固定相，并用元素分析、^13C固体核磁共振、红外光谱进行了表征。以甲醇和水为二元流动相，用包括碱性、酸性和中性有机化合物在内的混合物对该固定相进行评价，并考察了该填料的适用pH范围及水解稳定性。结果表明，该固定相具有较好的色谱性能，且在pH=2-8之间稳定性能良好，可有效地用于碱性化合物的分析分离。     

四苯基卟啉钴催化有机化合物与二氧化碳的电羧化反应Ⅱ.

研究了α、β、γ、δ－四苯基卟啉钴（ＣｏＴＰＰ）存在下苄基氯、苯乙酮、二苯甲酮和萘等与ＣＯ＿２的电羧化反应，与无催化剂体系相比，ＣｏＴＰＰ可使这些有机化合物与ＣＯ＿２电羧化反应的过电位降低约８００～１０００ｍＶ，对反应有较高的催化活性．用ＵＶ，ＩＲ和ＧＣ－ＭＳ确认了电羧化产物，并探讨了ＣｏＴＰＰ催化反应机理．     

β—环糊精键合固定相合成方法和色谱性能研究

以两种不同的路线合成β－环瑚精－环氧丙氧丙基键合硅胶固定相（β＿ＣＤ－ＧＰＳ）。比较了两种方法得到的键合相的键合量。采用非水滴定法考察了影响键合反应的因素。选择了合成β＿ＣＤ－ＧＰＳ最佳反应条件，并对其色谱性能进行了考察。     

β－蒎烯和马来酸酐的反应及产物表征

β－蒎烯和马来酸酐的反应及产物表征蒋旭红，蒋凤池（江西师范大学化学系，南昌３３００２７）Ｖｅｒｇｈｅｓｅ［１］曾经认β－蒎烯和ＭＡ相互作用时，ＭＡ只作为一种催化剂引起β－蒎烯重排（异构化）。Ａｒｎｏｌｄ［２］等对β－蒎烯和ＭＡ的反应进行研究时发现：β...     

苦杏仁甙化学发光生物传感器

将具有分子识别功能的β－葡萄糖甙酶和能进行换能反应的Ｌｕｍｉｎｏｌ分别固定在壳质胺和大孔阴离子交换剂的柱中,组成流动注射系统。苦杏仁甙在β－葡萄糖甙酶催化下分解生成的ＣＮ＾－（分子识别反应）与溶解氧反应生成超氧阴离子自由基,继而同Ｌｕｎｉｎｌ反应产生化学发光（换能反应）。这一新型生物传感器的化学发光强度与苦杏杜甙量在１～２００ｕｇ之间呈良好线性关系,检出限为０．３ｕｇ,相对标准偏差为３．１％,并具     

二烷基取代β—环糊精作毛细管气相色谱固定液的研究

合成了３种二烷基取代β－环糊精－七－（２，６－Ｏ－二丁基）－β－环糊精、七－（２，６－Ｏ－二戊基）－β－环糊精和七－（２，６－Ｏ－二己基）－β－环糊精，并用作毛细管气相色谱固定液，结果说明二丁基取代环糊精柱可涂渍成高效毛细管柱，对醇和酚类化合物异构体及一些对映异构体具有选择性分离能力。     

乳酸烷基酯在接枝聚硅氧烷β-环糊精固定相的手性拆分

采用新合成的手性接枝聚硅氧烷β－环糊精（二环「２，６－二－０－戊基－３－０－已烯基（－５）」五环「２，６－二－０－戊基－３－０－甲基」－β－ＣＤ－聚硅氧烷）固定相制备了毛细管气相色谱柱，对合成的不对称化合物乳酸烷基进行了有效的手性拆分，结果表明该固定相具有良好的手性分离能力。     

多胺修饰β-环糊精对铝-铁试剂荧光体系的增敏作用

研究了β－环糊精（1）、单－[6-乙二胺－6－脱氧]-β－环糊精（2）、单-[6-(二乙烯三胺）-6-脱氧]-β-环糊精（3）和单-[6-(三乙烯四胺）－6－脱氧]-β-环糊精（4）对铝－铁试剂荧光体系的增敏作用。实验结果表明：加入β－环糊精及其衍生物后体系的荧光强度均增强，增敏率为4＞3＞2＞1，其中4给出最大的荧光增敏率。研究了pH值在3.0-7.5之间酸度对主体化合物增敏能力的影响，发现体系的pH值对β－环糊精的增敏率影响较小，而随着体系酸性的增强，多胺修饰β－环糊精的增敏作用显著增强。探讨了修饰环糊精引入边臂的长度和主－客体间的尺寸适合等因素对铝－铁试剂体系荧光增敏率的影响。     

增效试剂对过氧化物模拟酶催化显色体系的增效作用——Fe-TPPS_4-4-AAP-苯酚衍生物-H_2O_2体系

本文以β－环糊精（β－ＣＤ）和表面活性剂为增效试剂，分别研究了它们对以Ｆｅ－ｍｅｓｏ－（四（４－磺基苯）卟啉）（Ｆｅ－ＴＰＰＳ４）为催化剂，催化过氧化氢氧化４－氨基安替比林（４－ＡＡＰ）与苯酚衍生物显色反应的速度和灵敏度的影响，发现β－ＣＤ和十二烷基苯磺酸钠（ＳＤＢＳ）对该体系具有明显的增效作用．在３×１０－３ｍｏｌ／Ｌβ－ＣＤ存在下，测定Ｈ２Ｏ２的灵敏度比文献报道的提高了１．５６倍．利用ＳＤＢＳ浓度与催化显色反应初速度的增加值之间的线性关系，建立了测定微量ＳＤＢＳ的方法     

葡萄糖苷特异性固相萃取固定相的合成、表征及应用

以马来酰亚胺基修饰凝胶载体,通过β-葡萄糖胺和2-亚氨基硫代烷盐酸盐将作为配基的β-葡萄糖脒连接到载体上,合成了一种葡萄糖苷特异性固相萃取固定相,并对其固相萃取性能进行了表征.该固定相对葡萄糖苷具有特异性识别,并成功用于固相萃取分离葡萄糖苷.     

反相液相色谱中固定相和流动相对柱相比的贡献

依据柱相比的热力学定义和反相液相色谱中溶质的计量置换保留理论(the stoichiometric dispheement heory of solute for retention，SDT-R)，对反相液相色谱中固定相和流动相性质、温度对柱相比的影响进行了研究。结果表明：固定相的种类和配基的疏水性对柱相比影响较大，而流动相中有机溶剂的种类，特别是脂肪酸作为置换剂时，对柱相比的影响更大，而柱相比受温度的影响较小。此外，通过用27种小分子溶质对柱相比的测定，其logI和Z良好的线性关系，进一步证明柱相比是一个与溶质性质无关的常数。     

Morphological studies of a hydrogen-bonded LC polymer obtained by photopolymerization in LC solvents

Anisotropic morphologies and the phase behaviour of a hydrogen-bonded LC polymer obtained by photopolymerization in two kinds of LC solvent are discussed. The hydrogen-bonded LC monomer, 4-(6-acryloyloxyhexyloxy) benzoic acid (A6OBA), was photopolymerized in 4-cyano-4′-hexyloxybiphenyl (6OCB) and in 4-cyano-4′-undecyloxybiphenyl (11OCB), which show a nematic phase and a smectic A phase, respectively. After photo-polymerization, the LC media were removed by extraction and the pure polymer was observed by scanning electron microscopy. SEM images showed that the polymer possessed fibrous morphology with a fibre diameter of a few micrometers, based on polymerization-induced phase separation. The overall geometries reflected typical LC characteristics such as schlieren and focal-conic fan textures. It was found that the hydrogen bond between benzoic acid groups in the monomer was rigid enough to fix the anisotropic phase-separated structure forming during the early stage of phase separation; however, it could not permanently maintain the fibre structure due to dissociation at elevated temperature. X-ray measurements revealed that a well developed layer structure of the hydrogen-bonded mesogen existed in the polymer obtained from the smectic phase of 11OCB, whereas a polymer layer structure could develop only partially from the nematic phase of 6OCB.     

亲水有机相-含盐水两相体系的形成机理与分相能力

亲水有机相-含盐水两相体系的形成机理与分相能力;亲水有机相;含盐水相;两相体系;分相机理;分相能力     

Oxadiazole-based unsymmetrical chiral liquid crystal dimers: synthesis and mesomorphic properties

The synthesis and liquid crystalline properties of novel chiral Schiff's base dimers containing the 1,3,4-oxadiazole ring are reported. The length of the terminal S-alkyl chain has been varied. All the compounds synthesised were thermally stable and exhibited enantiotropic mesomorphism, showing either SmC*–SmA–TGB–N*–BP or SmC*–SmA phase sequence.     

Cholesterol-based dimeric liquid crystals: synthesis,mesomorphic behaviour of frustrated phases and DFT study

Chiral unsymmetrical dimeric liquid crystals consisting of a cholesterol moiety as chiral entity and a substituted salicylidene imine core (with the substituent being butyl or fluoro or chloro group) interconnected through an even methylene spacer have been synthesised and their mesomorphic properties are characterised. All the dimers exhibit enantiotropic mesophases. The butyl homologue exhibited N* phase only, the fluoro- and chloro-substituted compound exhibited frustrated blue phases (BPs), N* phase and SmC* or twisted grain boundary (TGB) phases. The occurrence of a fluid frustrated phase, the BP, in particular, observed in compounds with a polar moiety and bent optimised conformation by density functional theory (DFT) study, indicates the importance of polar structures and bent shape of the compounds. Theoretical calculation was performed in order to study the optimised conformation, polarity and electron density distribution of the synthesised cholesterol derivatives using DFT. Time-dependent density functional theory (TD-DFT) calculation also had been carried out to investigate the absorption spectra and HOMO–LUMO energies. The experimental and theoretical absorption spectra are also presented.     

Preorganised effects of a tetramesogenic supermolecule on supramolecular assembly in the liquid crystalline phases

After preparing a homologous series of tetrameric mesogenic compounds in which two U-shaped molecules were connected via a rigid benzene derivative or a flexible alkyl chain, we investigated their phase transition behaviour using optical microscopy, differential scanning calorimetry and X-ray diffraction analysis. The compounds possessing an alkyl spacer as the central group exhibited nematic and smectic A phases just as the corresponding U-shaped molecule did. The compound possessing a 1,2-benzene unit as the connecting group showed nematic and smectic A phases, although the compound possessing a 1,3-benzene unit exhibited only an anticlinic smectic C phase. Structure–property relations of the liquid crystalline tetramers are interpreted in terms of preorganised effects of the four mesogenic units.     

Time‐Resolved Phase Transitions of the Nanocrystalline Cubic to Submicron Monoclinic Phase in Zirconia

The nanocrystalline cubic, tetragonal, and submicron monoclinic phases of pure zirconia were prepared by thermal decomposition of carbonate and hydroxide precursors. The crystallization and isothermal phase transformations of the oxide were studied using high temperature X‐ray diffraction, X‐ray diffraction and Raman spectra of quenched samples. Cubic zirconia formed first, and then progressively transformed to tetragonal and monoclinic phases at temperatures as low as 320°C. The cubic, tetragonal, and monoclinic phases for ZrO₂ were found to be distinct functions of crystallite size, indicating the nanocrystalline nature of these phases. They were found to exist within critical size ranges of 50 to 140 Å, 100 to 220 Å and 190 to 420 Å (±5 Å), respectively. Thus, as the crystallites grow during annealing, they first transform from cubic to tetragonal and then from tetragonal to monoclinic at critical sizes. The classical Avrami equation for nucleation and growth was applied to the tetragonal to monoclinic phase transition.     

Phase equilibria in the GeSe2-SnTe system

Journal of Thermal Analysis and Calorimetry - The phase diagram of the system GeSe2-SnTe is studied by means of X-ray diffraction, differential thermal and measurements of the microhardness and the...     

Physical properties of two systems with induced antiferroelectric phase

Two ferroelectric three‐ring chiral esters, one with a partially fluorinated alkyl chain and another with a cyano terminal group, were mixed with a structurally similar compound having an alkyl terminal chain. In their mixtures an antiferroelectric phase was induced. The phase behaviour, spontaneous polarisation, tilt angle, smectic layer spacing and helical pitch of both systems were determined. The mechanism of the induction of an antiferroelectric phase is different in both cases, with highly tilted phases in former system and less tilted phases in the latter.