聚丁二烯的链节结构与其氧化性能的关系

利用不同催化剂体系的定向聚合,可使丁二烯聚合成双键在主链和侧基中分布不同的聚合物。对于这些聚合物的氧化性能,尽管早期有人利用不同单体单元的均聚物和共聚物如天然胶、古塔坡胶以及丁钠、丁锂、丁苯、丁基胶等作过比较,认为丁二烯橡胶分子主链和乙烯侧基上所含双键的比例可以极大地影响其反应能力,主链上双键在氧化时较活泼,而乙烯侧基上的双键则在热交联时较活泼。     

对二氨基二苯型芳酰胺类液晶化合物的合成与表征

液晶作为新型材料,在高新技术领域显示出越来越广阔的应用前景,目前科学界对各种类型的液晶,包括主链型,侧链型液晶以及热固性液晶方面的研究非常活跃~([1-4]).含有端烯类双键的液晶化合物,可以通过双键联结到高分子链上,形成高分子液晶化合物,也可与其它烯类单体发生共聚合反应,制备液晶热固性树脂,还可以通过双键氧化,制备液晶环氧树脂,因此有广泛的应用前景~([5,6]).     

多羟基甾醇的合成及其结构与抗肿瘤细胞活性关系研究

报道了6个具有类似结构的多羟基甾醇的合成和它们的抗肿瘤细胞活性.发现此类化合物的细胞毒性与其分子中双键存在与否有着密切关系.当甾核或支链中双键被饱和时,其细胞毒性均明显降低.甾醇(5)和(8)对胃癌(MGC)、宫颈癌(HELA)细胞的生长具有一定的抑制作用.     

气相色谱和色-质谱法测定昆虫性信息素双键位置的研究

昆虫性信息素是一种微量生物活性物质,通常每头雌蛾中的含量仅毫微克,它们的结构大部分是直碳链不饱和的醛,醇及其酯。因此测定昆虫性信息素的双键位置是通过简易的操作在双键上进行化学反应,然后用高灵敏度的GC和GC/MS 进行检测。本文主要介绍用臭氧化或将双键转化为环氧,甲氧基等微量测定昆虫性信息素双键位置的方法:     

甾体植物生长激素的研究II:从猪去氧胆酸立体选择性合成(22S,23S)-香蒲甾醇

本文报道以猪去氧胆酸为原料,立体选择性地合成(SS2,23S)-香蒲甾醇,合成的关键步骤是用Li2Cu3(CH3)5立体专一地转化烯丙醇苯胺基甲酸酯10和13成为11和用OsO4-NMO在化合物16的不饱和侧链上立体选择性羟基化。     

化学修饰在质谱中的应用 3: 环丙烷脂肪酸的苯并 唑衍生物的质谱特征

本文作者曾成功地利用苯并 唑衍生物直接鉴定出不饱和脂肪酸中酸双键位置。本文在该基础上继续研究了长链环丙烷酸的苯并 唑衍生物的质谱, 结果证明脂肪链上的环丙烷基部位在其质谱上可得到特征的反映, 根据谱中碳链系列离子峰的质量间隔, 就可确定出环丙烷基在脂肪链的位置。     

化学修饰在质谱中的应用 3: 环丙烷脂肪酸的苯并 唑衍生物的质谱特征

本文作者曾成功地利用苯并 唑衍生物直接鉴定出不饱和脂肪酸中酸双键位置。本文在该基础上继续研究了长链环丙烷酸的苯并 唑衍生物的质谱, 结果证明脂肪链上的环丙烷基部位在其质谱上可得到特征的反映, 根据谱中碳链系列离子峰的质量间隔, 就可确定出环丙烷基在脂肪链的位置。     

β-谷甾醇、豆甾醇与DPPC相互作用的单分子膜研究

植物甾醇对生物膜具有重要的调节作用,甾醇尾部的饱和程度对生物膜性质的影响一直是个热点问题.通过LB技术和原子力显微镜分别研究了尾部是单键的β-谷甾醇(β-sito)和尾部是双键的豆甾醇(stig)与二棕榈酰磷脂酰胆碱(DPPC)的相互作用,深入分析了β-谷甾醇、豆甾醇对DPPC单分子膜液态扩张-液态聚集(LE-LC)相变过程的影响.实验结果表明:β-谷甾醇、豆甾醇添加到DPPC单分子膜中,膜的压缩性以及分子的排列都发生了较大变化.当植物甾醇含量Xsterols=0.8时,β-谷甾醇、豆甾醇与DPPC相互作用具有相同的规律,过量分子面积和过量吉布斯自由能均为负值,说明分子间的吸引力比排斥力更强;在低浓度下,Xsterols=0.2,0.4时,两种系统的过量分子面积和过量吉布斯自由能呈现出明显的区别,尾部是单键的β-谷甾醇和DPPC混合单分子膜的排斥力更强烈,而尾部是双键的豆甾醇和DPPC混合单分子膜的吸引力更强烈,说明尾部是双键的豆甾醇比尾部是单键的β-谷甾醇更容易和DPPC发生凝聚,AFM数据进一步证实了这些结果.     

油菜甾醇内酯及其类似物的侧链部分合成新方法

以豆甾醇为原料，合成了油菜甾醇内酯及其类似物的侧链部分；并为这一类化 合物的侧链部分的合成提供了一条简便、经济、高效的合成方法。其关键步骤为醛 5及酮6之间的不对称Aldol反应，以及羰基α位的差向异构化反应。     

多羟基甾醇的合成及其结构与抗扣瘤细胞活性关系研究

报道了６个具有类似结构的多羟基甾醇的合成和它们的抗肿瘤细胞活性。发现此类化合物的细胞毒性与其分子中双键存在与否有着密切关系。当甾核或支链中双键被饱和时，其细胞毒性均明显降低。甾醇（５）和（８）对胃癌（ＭＧＣ）、宫颈癌（ＨＥＬＡ）细胞的生长具有一定的抑制作用。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

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.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

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。