几种环糊精衍生物手性固定相与OV—1701或OV—7混和离析氨基酸,羟基酸…

本实验合成了２，６－０－二丁基－３－０－三氟乙酰基－γ－环糊精，２，６－０二戊基－３－０三氟乙酰基基－β－环糊精，全戊基－β－ＣＤ。分离了一些氨基酸酯，羟基酸酯，卤代酸酯，卤代烃，醇等对映体。比较了ＯＶ－７和ＯＶ－１７０１作混合固定相稀释液对离析性能的影响。     

几种环糊精衍生物手性固定相与OV－1701或OV－7混和离析氨基酸、羟基酸等对映体

本实验合成了２，６－０－二丁基－３－０－三氟乙酰基－γ－环糊精、２，６－０－二戊基－３－０－三氟乙酰基－β－环糊精、全戊基－β－ＣＤ。分离了一些氨基酸酯、羟基酸酯、卤代酸酯、卤代烃、醇等对映体。比较了ＯＶ－７和ＯＶ－１７０１作混合固定相稀释液对离析性能的影响。     

两种β－环糊精衍生物手性石英毛细管柱拆分对映体

合成了全戊基化（Ⅰ）和部分戊基化三氟乙酰化（Ⅱ）的两种“环糊精手性固定相。将它们分别与ＯＶ－７混合制备出柱效大于４１００塔片／ｍ，热稳定性可达２１０℃的手性石英毛细管住。对映体拆分结果表明，固定相Ⅰ对醇、二醇、胺、γ－内酯等对映体比Ⅰ有更高的选择性。     

两种β－环糊精衍生物手性石英毛细管柱拆分对映体

 合成了全戊基化（Ⅰ）和部分戊基化三氟乙酰化（Ⅱ）的两种“环糊精手性固定相。将它们分别与ＯＶ－７混合制备出柱效大于４１００塔片／ｍ，热稳定性可达２１０℃的手性石英毛细管住。对映体拆分结果表明，固定相Ⅰ对醇、二醇、胺、γ－内酯等对映体比Ⅰ有更高的选择性。     

盐酸美西律对映体的毛细管电泳分离

以β－环糊精的两种生物做为毛细管电泳手性分离添加剂，对盐酸美西律的对映体进行了拆分研究。其中，２，６－Ｏ－二甲基β－环糊精可将对映体部分拆分，而２，３，６－Ｏ－三甲基β－环糊精时，可基线分离对映体。研究了两种甲基化β－环糊精的浓度及工作电压对分离的影响。     

β—环糊精衍生物手性固定相的研究及应用

合成了一种新的手性固定相２,６-Ｏ-二庚基-３-Ｏ三甲基硅烷基-β环糊精，以甲基苯硅油为稀释剂，采用快速超动态法，成功地制备了高效手性毛细管柱，考察了手性柱的色谱性能，分离了醇、酮、烯烃类等一些对映体。     

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。     

三种烷基化和硅烷化β-环糊精作为气相色谱固定相的研究

合成了三种新的烷基化和硅烷化β－环糊精衍生物手性固定相，以甲基苯基硅油为稀释剂，采用快速超动态法，成功地将其涂渍到弹性石英毛细管柱上，经测试，柱效高，柱性能稳定，柱寿命较长，通过对酯类，烯烃类，酮类等对映体色谱分离，显示三种固定相具有较强的手性拆分能力，随着烷基链的增长，对α－蒎烯，β－蒎烯，α－紫萝酮等拆分能力逐渐增强，而对α－苯乙醇，1，20丙二醇，乳酸乙酯等对映体的拆分能力逐渐减弱。     

手性毛细管气相色谱法测定微生物产生的环氧化物的对映体组成

在选择的修饰β－环糊精中,２,６－Ｏ－二戊基－３－Ｏ－三氟乙酰基－β环糊精（２,６－Ｏ－ＤＰ－３－Ｏ－ＴＦＡ－β－ＣＤ）是毛细管气相色谱法分离１－氯（溴）－２,３－环氧丙烷对映体较好的手性固定相,环氧丙烷对映体即使在室温下也不能拆分。由五株甲烷利用菌和一株乙烯利用菌产生的３－氯（溴）－１,２－环氧丙烷的对映体组成的测定结果表明,甲烷利用菌形成外消旋环氧化物,乙烯利用菌主要形成（Ｓ）－１－氯－２,３－环氧丙烷     

不同稀释剂对改性环糊精手性分离的影响

用α－苯乙胺、反式－二氯菊酸甲酯做手性试剂,考察了５种稀释剂稀释２,６－二－Ｏ－Ｔ基－３－Ｏ＝丁酰基－β－环糊精的对映体拆分效果。结果表明,用ＳＰ－７９做知释剂与ＯＶ－７、ＯＶ－１７０１、ＳＥ－５４、ＰＥＧ－２０Ｍ等相比,前者有基本相同的柱效、略高或基本一致的对映体选择性。通过焓熵关系分析发现,选用所述不同稀释剂不改变手性拆分机制。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

化学计量中不确定度评定研究进展

测量不确定度是表征合理地赋予被测量之值的分散性的参数。本文针对化学计量不确定度评定基础模型仅适用于线性模型、概率分布为正态分布或缩放位移t分布等局限,介绍了近年来不确定度评定的研究热点:蒙特卡罗方法(Monte Carlo Method,MCM),不确定度评定的来源、评定概念、评估方法及其发展过程,扩大了测量不确定度评定与表示的适用范围。