苯基修饰β-环糊精的自组装行为

利用X射线衍射分析和核磁方法研究了单(6-氧-6-苯基)-β-环糊精(1)在固态和液态中的分子自组装行为. 结果表明, 在固态中连接于环糊精主面的芳香基团从次面插入到另一个环糊精的空腔形成了二重对称轴的螺旋结构; 在溶液中该修饰环糊精自组装形成聚集体的键合常数为240 mol^-1·L. 这些研究结果与报道的单(6-脱氧-6-苯胺基)-β-环糊精(2)、单(6-脱氧-6-苯硒基)-β-环糊精(3)和单(6-脱氧-6-苯巯基)-β-环糊精(4)一起, 进一步揭示了分子自组装形成超分子的一些控制因素.     

毛细管气相色谱法分离2-苯基羧酸酯对映体

手性2-芳基羧酸酯是制备手性非甾体抗炎药物2-芳基羧酸的重要的中间体,为了建立可用于2-苯基羧酸酯对映体分离的手性毛细管气相色谱法(CGC),分别使用2,6-二-O-戊基-3-O-丁酰基-β-环糊精及2,6-二-O-苄基-3-O-庚酰基-β-环糊精作毛细管气相色谱手性固定相,研究了其对2-苯基丁酸甲酯、2-苯基丁酸乙酯、2-苯基丁酸异丙酯、2-苯基丙酸甲酯及2-苯基丙酸环戊酯等5种2-苯基羧酸酯对映体的分离能力。结果表明,用2,6-二-O-戊基-3-O-丁酰基-β-环糊精及2,6-二-O-苄基-3-O-庚酰基-β-环糊精作手性固定相的毛细管气相色谱法可以分离2-苯基丁酸甲酯、2-苯基丙酸甲酯和2-苯基丙酸环戊酯对映体。2,6-二-O-戊基-3-O-丁酰基-β-环糊精对3种2-苯基羧酸酯对映体的分离能力超过了2,6-二-O-苄基-3-O-庚酰基-β-环糊精。     

双敏感性环糊精超分子聚集体的制备及其性能研究

利用光敏感性环糊精衍生物与温度敏感性聚合物主客体间的包结络合作用制备了具有光/温度双敏感性的环糊精超分子聚集体. 首先制备了主体分子光敏感性4-羟基肉桂酸-β-环糊精(4HCA-CD); 再以末端带金刚烷基团(AD)的三硫酯作为链转移剂, 用可逆加成-断裂链转移自由基聚合(RAFT)法制备温度敏感性双臂聚合物AD-PNIPAM-AD; 用傅里叶变换红外光谱(FT-IR)、核磁共振氢谱(¹H NMR)证明了化合物的结构. 利用β-CD的疏水空腔和AD之间的络合性能, 制备了4HCA-CD/AD-PNIPAM-AD双敏感性超分子复合物, 通过二维核磁(2D NMR)对其包结性能进行了探究, 结果证实金刚烷包结于环糊精的空腔中. 所得4HCA-CD/AD-PNIPAM-AD复合物具有光敏感性, 用紫外光照射后, 复合物的分子量增大近一倍. 而且, 4HCA-CD/AD-PNIPAM-AD复合物可以自组装形成超分子聚集体, 其粒径随温度的升降发生可逆的减小或增大.     

滇桂艾纳香多糖BRP的结构解析

以滇桂艾纳香为原料, 经热水抽提、Sevag法除蛋白、醇沉、DEAE-纤维素柱层析、Sephadex G-200、Sepharose 6 F.F.凝胶色谱纯化得到纯品BRP|经HPGPC检测分析表明, BRP为均一多糖, 分子量为3.3×10⁴ Da|用UV、IR、HPLC、HPGPC、GC-MS、甲基化、NMR (¹H NMR、¹³C NMR、HMQC、HMBC)等方法对BRP结构进行表征, 结果表明, BRP仅由呋喃果糖残基组成, 以→2)Fruf (1→ (或→1)Fruf (→2)方式链接, 推导其结构式为: β-D-Fruf-{2[→1)- β-D-Fruf(2→]_n-1}-β-D-Fruf .     

电流滴定法对两种短链分子自组装膜的研究

把带有—NH2的半胱胺和4-氨基硫酚两种短链分子组装到金电极上,形成自组装单分子膜;两种自组装膜在[Fe(CN)6]3-/4-溶液中进行循环伏安扫描时,出现了不同于长链分子自组装膜的行为:峰间距变窄、峰电流变大的现象,这是由于两者在金上组装不够致密,以及末端的—NH2存在对[Fe(CN)6]3-/4-的影响造成的。通过改变溶液的pH,研究溶液中H 浓度对半胱胺自组装膜和4-氨基硫酚自组装膜在[Fe(CN)6]3-/4-溶液中电化学行为的影响;通过电流滴定的方法求算出半胱胺自组装膜和4-氨基硫酚自组装膜的表面pKb分别为2.4±0.2和4.7±0.2;通过在碱性条件下的循环伏安图,对两者的组装效果进行了比较。     

齐墩果烷型和乌苏烷型五环三萜同分异构体配位色谱法分离机理（英文）

本文主要研究了配位色谱法分离齐墩果烷型和乌苏烷型五环三萜同分异构体的分离机理。基于计算模拟分析,β-环糊精（β-CD）和其衍生物为适宜的配位剂。采用HPLC法测定了包合物的表观形成常数,并制备了asiaticoside-B与β-CD包合物。实验结果显示:流动相中添加葡萄糖基-β-环糊精（Glu-β-CD）时,同分异构体的分离度为11.95,比添加β-CD或添加甲基-β-环糊精（DM-β-CD）时（分别为9.61和9.89）都略高些。假定五环三萜类化合物与β-CD形成1：1的包合物,对于asiaticoside-B,流动相中添加Glu-β-CD时,表观形成常数（K_F）为2534 L/mol,比添加β-CD或添加DM-β-CD时（分别为1467和1373 L/mol）都略大些。根据asiaticoside-B与β-CD包合物的红外光谱解析及计算模拟,推测asiaticoside-B的E环上甲基部分进入了β-CD的空腔内,而其羰基基团没有进入β-CD的空腔内,其糖苷部分与亲水性的β-CD空腔外部形成氢键作用力。因此,配位色谱法分离齐墩果烷型和乌苏烷型五环三萜同分异构体的分离机理可以推测如下：齐墩果烷型和乌苏烷型五环三萜同分异构体E环上甲基的不同空间位阻导致了同分异构体的不同色谱分离行为。     

碳-氟键断裂用于构建氟代异噁唑化合物

含氟异噁唑骨架是许多药物及农药分子中的重要结构单元,其中单氟代异噁唑类化合物的合成方法还比较有限.从易得的α-三氟甲基-β-羰基酯出发,发展了基于碱促进的碳氟键断裂策略的氟代异噁唑化合物合成方法,该反应条件温和,操作简便,官能团兼容性良好,可以中等到较好的收率得到一系列3-氟代异噁唑化合物,且所得产物可进一步转化为生物活性分子的类似物.     

Janus超支化超分子聚合物的构筑及电化学响应性自组装行为研究

本工作报道了第一例具有电化学氧化还原刺激响应性的Janus超支化超分子聚合物,研究了其自组装及响应性解组装的行为.通过阴离子开环聚合和阳离子开环聚合的方法,分别合成了以β-环糊精为中心的亲水超支化聚缩水甘油醚CD-g-HPG和末端为二茂铁的疏水超支化聚（3-乙基-3-羟甲基环氧丁烷）Fc-g-HBPO.两者通过Fc/CD之间的主客体包结络合作用,构筑了两亲性Janus超支化超分子聚合物HBPO-b-HPG.该聚合物在水中可以自组装形成囊泡.通过动态光散射（DLS）跟踪、2D-NOESY和循环伏安曲线表征了CD-g-HPG和Fc-g-HBPO之间的主客体包结络合作用,通过扫描电子显微镜（SEM）和透射电子显微镜（TEM）表征了囊泡结构.最后,研究了囊泡在电化学刺激下的解组装行为,同时也验证了囊泡在加热、加入主客体竞争分子和化学氧化下的稳定性.     

八面体纳米笼构筑的金属-有机框架化合物

利用半刚性的三足羧酸配体1,3,5-tris[3-(carboxyphenyl)oxamethyl]-2,4,6-trimethylbenzene acid (H₃TBTC)与金属离子自组装成功合成了两例八面体纳米笼构建的金属-有机框架化合物: {[Zn₃TBTC₂(DMA)(H₂O)]·3DMA·3H₂O}_n (1), {[Cd₃TBTC₂(DMA)₂(H₂O)₂]·2DMA·2H₂O}_n (2). TBTC^3-配体在化合物中呈现出cis,cis,cis-和cis,trans,trans-两种构型. cis,cis,cis-构型的TBTC^3-配体与Zn₃(COO)₆次级结构基元(secondary building units, SBUs)构筑了畸变的八面体金属-有机纳米笼, 因而化合物的结构可以看成是八面体金属-有机纳米笼作为超分子构建单元(supramolecular building blocks, SBBs), 在空间上与cis,trans,trans-构型的配体相连, 最终形成具有(3,18)-连接的三维无限网络. 荧光测试结果表明, 化合物1～2的荧光都是基于配体的发射. 相对于配体的发射光谱, 化合物1～2的发射光谱展现出蓝移的现象. 气体吸附测试结果表明, 化合物1～2具有选择性吸附二氧化碳的能力.     

基于杯芳烃主体的分子自组装研究进展

分子自组装是超分子化学最重要的研究内容之一. 杯芳烃作为继冠醚、环糊精之后的第三代人工合成受体分子已在分子自组装研究方面取得了重要进展并显示了广泛的应用前景. 主要综述杯芳烃衍生物通过氢键、金属诱导配位、π-π作用、疏水作用等非共价键弱相互作用力在溶液状态、固态和界面的分子自组装方面的研究进展.     

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.     

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.     

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.     

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^-。     

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.     

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.