2,5-二[5-(对癸氧基苯基)-1,3,4-噁二唑]乙烯基苯与乙烯基咔唑共聚物的合成与表征

通过自由基聚合反应得到了2,5-二[5-(对癸氧基)苯基)-1,3,4-噁二唑]乙烯基苯和乙烯基咔唑的无规共聚物.研究了共聚物组成与热性能关系;实验结果表明,随着乙烯基咔唑量的增加,共聚物的荧光量子产率会下降;共聚物与相应的均聚物相似,它们具有相似的光致发光波长.     

(乙烯基咔唑-甲基丙烯酸金刚烷酯)共聚物的制备与光致发光性能

以1-金刚烷醇和甲基丙烯酰氯为原料,经酯化反应合成甲基丙烯酸金刚烷酯单体。然后通过甲基丙烯酸金刚烷酯与N-乙烯基咔唑进行共聚反应合成了乙烯基咔唑-甲基丙烯酸金刚烷酯共聚物。采用1H-NMR、FI-IR和元素分析等表征了共聚产物的结构,通过凝胶渗透色谱仪和荧光光谱仪考察了金刚烷基团对共聚物结构与荧光性能的影响。     

N-(2-溴乙基)咔唑与N-乙烯基咔唑的气相HeI紫外光电子能谱与电子结构研究

首次报道了N-(2-澳乙基)咔唑和N-乙烯基咏唑的气相Hel紫外光电子能谱(UPS),借助于Gaussian 94采用RHF/6-3lG基组优化几何构型,并用RHF/6-31G基组计算分子轨道及能级.在对咔唑和N-烷基咔唑系列分子UPS电离能变化规律研究的基础上,对这2个分子的UPS谱带给予指认,并讨论其电子结构.结果表明N-(2-溴乙基)咔唑的UPS谱与N-烷基咔唑的不同之处是在10.295,10.540Ve处出现2个Br原子的孤对轨道;N-乙烯基咔唑的UPS谱带与咔唑的相比,电离能变化的特殊性说明乙烯基与咔唑环共平面.     

N-(2-溴乙基)咔唑与N-乙烯基咔唑的气相HeI紫外光电子 能谱与电子结构研究

首次报道了N-(2-溴乙基)咔唑和N-乙烯基咔唑的气相HeI紫外光电子能谱(UPS),借助于Gaussian94采用RHF/6-31G基组优化几何构型,并用RHF/6-31G^*基组计算分子轨道及能级.在对咔唑和N-烷基咔唑系列分子UPS电离能变化规律研究的基础上,对这2个分子的UPS谱带给予指认,并讨论其电子结构.结果表明N-(2-溴乙基)咔唑的UPS谱与N-烷基咔唑的不同之处是在10.295,10.540eV处出现2个Br原子的孤对轨道;N-乙烯基咔唑的UPS谱带与咔唑的相比,电离能变化的特殊性说明乙烯基与咔唑环共平面。     

汞代N-乙烯基咔唑-丙烯酸共聚物的合成与研究

制备线型和网状N-乙烯基咔唑-丙烯酸甲酯共聚物后,用三氟乙酸汞分别在四氢呋喃(THF)和二氯甲烷中进行汞化反应,得到相应的线型和网状汞代咔唑共聚物。这些共聚物经THF溶解或溶胀后,用氢氧化钠水溶液水解,得到相应的水溶性线型高分子和吸水性网状高分子,憎水性汞代咔唑共聚物在THF中由I₂取代汞;亲水性汞代咔唑共聚物在水溶液中由KI₃取代汞。汞代咔唑高分子链在不同溶剂中可以产生不同的形态变化。     

高分子三线态敏化剂分子中能量迁移的研究 Ⅰ.聚(乙烯基二苯酮-β-乙烯基萘)中的能量迁移的研究

本工作对乙烯基二苯酮-β-乙烯基萘共聚物体系分子内的能量迁移和转移进行了研究.在77K玻璃态溶液中,不论以310nm或以370nm波长激发时,共聚物都发生强的萘燐光.各共聚物三线态能量转移量子效率φ_(ET)~(T-T)大于80％,表明此高分子体系能有效地进行三线态能量迁移和转移.     

聚(4-乙烯基吡啶)-b-聚环氧乙烷-b-聚(4-乙烯基吡啶)的合成及其用于毛细管电泳分离碱性蛋白质

用原子转移自由基聚合(ATRP)法合成了结构可控的三嵌段共聚物聚(4-乙烯基吡啶)-b-聚环氧乙烷-b-聚(4-乙烯基吡啶)(P4VP-b-PEO-b-P4VP).用核磁共振氢谱和凝胶渗透色谱对该共聚物进行了表征;将该共聚物作为毛细管物理吸附涂层,用毛细管电泳对碱性混合蛋白质进行了分离.结果表明:蛋白质的分离效率随着P...     

3,6-二(蒽醌-2-乙烯基)-N-乙基咔唑的合成及光谱性质研究

利用N-乙基咔唑和2-甲基蒽醌合成了一种A-π-D-π-A分子内电荷转移型化合物3,6-二(蒽醌-2-乙烯基)-N-乙基咔唑,并对该化合物的光化学和光物理行为进行了研究。荧光光谱表明,该化合物的发光行为对溶剂的极性非常敏感,随着溶剂极性的增大,其荧光最大发射峰有明显红移,并在强极性溶剂乙腈中出现了双荧光现象。该化合物的激发态和基态的偶极矩差值△μ为3.014D,发生了从给体(咔唑基)的N原子到分子两端受体(蒽醌)的羰基的分子内电荷转移。     

б-(甲酰乙烯基)二氢卟吩衍生物的合成

以脱镁叶绿酸-a甲酯为原料,利用Vilsmeier反应合成б-(甲酰乙烯基)二氢卟吩衍生物.镍(II)脱镁叶绿酸-a甲酯和镍(II)红紫素-18与Vilsmeier试剂作用,生成了E环被打开的镍(II)б-(甲酰乙烯基)红紫素-7-三甲酯和镍(II)б-(甲酰乙烯基)二氢卟吩P6三甲酯.镍(II)N-乙酰氧基红紫素-18-酰亚胺和Vilsmeier试剂作用,生成了镍(II)б-(甲酰乙烯基)-N-_乙酰氧基红紫素-18-酰亚胺.当这些化合物脱去镍离子后,吸收波长明显红移,б-(甲酰乙烯基)-N-乙酰氧基红紫素-18-酰亚胺的吸收波长达到742 nm.同时保留了对б-位再进行化学修饰的可能性.合成的新化合物均由核磁共振、红外光谱、元素分析和质谱予以证实.     

(E)-N-芳基-3-[2-(8-羟基喹啉基)-乙烯基]咔唑的合成、抗氧化活性及促进鼠骨髓间质干细胞增殖的研究

设计合成了3-[2-(8-羟基喹啉基)-乙烯基]-N-对甲苯基咔唑(8)和3-[2-(8-羟基喹啉基)-乙烯基]-N-对甲氧苯基咔唑(9)两个新的化合物, 用IR, MS, 1H NMR和元素分析确认其结构. 并利用DPPH•方法, 超氧阴离子自由基( )法, 羟基自由基HO•法和噻唑蓝比色法(MTT法)分别测定了目标产物的抗氧化活性和调控鼠骨髓间质干细胞(MSCs)的作用. 结果表明, 这两种化合物对DPPH•自由基、超氧阴离子自由基和羟基自由基具有较强的抗氧化活性, 化合物9在低浓度时对鼠骨髓间质干细胞增殖有很好的促进作用.     

SYNTHESIS AND REACTIONS OF SOME 2-THIENYL- AND 2-THENOYL-DERIVATIVES OF THIAZOLE AND THIADIAZOLINE AND THEIR SELENIUM ANALOGS

Abstract

2-(Thiocyanatoacetyl)thiophene 2 and its selenium analog 3 couple with diazotized anilines and yield 3-aryl-2-imino-5-(2-thenoyl)-2,3-dihydro-1,3,4-thiadiazoles 6 and 3-aryl-2-imino-5-(2-thenoyl)-2,3-dihydro-1,3,4-selenadiazoles 7 respectively. The reactions of both 6 and 7 with nitrous acid, acetic anhydride and benzoyl chloride are described. Azo coupling of 2-amino-4-(2-thienyl)thiazole 17 and its selenazole analog 18 with diazotized anilines yielded the arylazo derivatives 19 and 20 respectively. Reaction of the hydrazidoyl bromide 16 with potassium thiocyanate, potassium selenocyanate, thiourea and selenourea yields 6, 7, 19, and 20 respectively.     

PHOTOLYSIS AND RADIOLYSIS OF NITROMETHANE AND NITROETHANE

Abstract— Prolonged photolysis of nitromethane and nitroethane in liquid and vapour phases, with simultaneous photolysis of the nitrogen dioxide formed, was studied in the absence and presence of cupric oxide. A high-pressure quartz immersion lamp providing the full range of visible and u.v. spectrum, with a high output of radiation at 366 and 313 mμ, was employed as source of light. The products of photolysis were detected by microanalytical methods, infrared-absorption spectrum analysis and gas chromatography. Photolysis of liquid nitro-alkanes resulted in formation of many compounds; saturated hydrocarbons, and in the case of nitroethane, ethylene, were submitted to detailed examination. Photolysis in the vapour phase was carried out in a specially designed glass apparatus. The main products were nitrogen dioxide, aldehydes and polyaldehydes; hydrocarbons were not estimated.
Liquid nitromethane and nitroethane were also irradiated with γ-rays from a ⁶⁰Co source. The radiolysis products were similiar to those obtained on photolysis. The mechanism of photolytic decomposition of nitroalkanes is proposed and discussed.     

聚壬酰胺的制备纺丝及结构与性能测定

9-氨基壬酸系从癸二酸经单酯化、氨化和Hofmann重排制得。该单体以10克规模在玻璃管中和以4公斤量在15升聚合釜中,于260℃聚合成聚壬酰胺。聚合物在288℃纺丝,120℃牵伸,得到尼龙-9纤维。测定了聚合物和纤维的结构和多种性能。     

温度及pH敏感N-异丙基丙烯酰胺/β-环糊精水凝胶的合成与性能研究

用顺丁烯二酸酐 (MAH)对具有分子包结能力的 β 环糊精 (β CD)进行化学改性 ,合成出了丁烯二酸单酯化 β CD单体 (MAH β CD) .通过氧化还原自由基引发MAH β CD与N 异丙基丙烯酰胺 (NIPA)聚合 ,合成出含 β CD结构单元的新型水凝胶 .用核磁共振、红外光谱及元素分析对MAH β CD单体及共聚物的结构和组成进行了表征 .溶胀研究结果表明 ,该水凝胶具有较好的pH、温度及离子强度敏感性 ;并且水凝胶在较高羧基(—COOH)含量和弱碱环境中 ,仍能表现出明显的温敏性     

生物质热解、加氢热解及其与煤共热解的热重研究

在加压热天平上用非等温热重法进行生物质（锯末、稻壳）在Ｎ２气氛下的热解和加氢热解研究。考察了升温速率（５～２５℃／ｍｉｎ）和压力（０．１～７ＭＰａ）的影响，求取了热解动力学参数，并研究了生物质与煤在常压Ｎ２气下的共热解过程。研究结果表明：生物质在４００℃左右即完成热解反应，总失重率大于７０％（Ｗ％，ｄａｆ．），热解时仅一个峰位于３００℃左右；与煤热解行为相同，随升温速率及压力的升高，转化率下降，ＤＴＧ峰移向高温，但由于热解反应在较低温度下进行，氧气的存在对生物质热解ＴＧ和ＤＴＧ的影响远小于煤热解。证明生物质热解以其内部氢对自由基的饱和及分子重排反应为主。生物质热解可用一级反应动力学处理，主要热解阶段及表现活化能分别为：锯末，２６７～３１４℃，６９．６６ｋＪ／ｍｏｌ；稻壳，２８３～３１０℃，５３．４５ｋＪ／ｍｏｌ；生物质由于与煤的热分解温度相差很大，因而在其共热解过程中无协同作用。     

CHLOROPHYLL a AND CAROTENOID AGGREGATES AND ENERGY MIGRATION IN MONOLAYERS AND THIN FILMS

Abstract— The spectra of absorption, fluorescence and excitation of monolayers and thin films containing chlorophyll a together with a carotenoid (cis-β-carotene, trans-β-carotene, fucoxanthin, or zeaxanthin), were measured at — 196°C. The concentration ratios used, (Chl)/(Car), were 6:1, 4:1, 3:1, 2:1, 1:1 and 1:3, and the area densities, 3·70, 2·55, 1·76, 0·71, 0·37 and 0·17 nm²/pigment molecule. In dilute monolayers, (3·70 nm²/molecule), with a constant concentration ratio (Chl)/(Car) = 3:1, evidence of three β-carotene forms, with absorption bands at 460, 500 and 520 nm (C₄₆₀, C₅₀₀ and C₅₂₀), and of a chlorophyll a form with an absorption band at 669–672 (Chl_669–672) was found. On increasing the density to 0·2–0·3 nm²/molecule, a conversion of C₄₆₀ and C₅₂₀ into C₅₀₀, was observed, and several more additional (probably more strongly aggregated) chlorophyll a forms appeared, with absorption bands at 672–733 nm. With excess carotene [(Chi)/(Car) = 1:3] the forms C₄₆₀, C₅₀₀, C₅₂₀ and Chl_669–672 were present even in the most dense films (0·2–0·3 nm²/molecule). The same was found with other carotenoids: if one of the pigments was in excess, aggregated forms of the other tended to disappear. In the transfer of energy from carotenoids to chlorophyll a, C₅₀₀ was found to be the main donor. In layers with a concentration ratio (Chl)/(Car) = 3:1, the efficiency of transfer was less than 10 per cent at the lowest density used (3·70 nm²/molecule); it increased to 50 per cent, as the density was increased to 0·20 nm²/molecule. When the relative concentration of the carotenoid was increased to (Chl)/(Car) = 1:1, the efficiency of energy transfer dropped to 25 per cent even at 0·20 nm²/molecule. It seems that the efficiency of energy transfer between carotene molecules (prior to its transfer to chlorophyll a) is low, and effective transfer occurs only between β-carotene and immediately adjacent chlorophyll a molecules.     

SURFACE ENTHALPY AND ENTROPY AND THE PHYSICO-CHEMICAL NATURE OF HYDROPHOBIC AND HYDROPHILIC INTERACTIONS

The attractive Interactions between typically hydrophobic molecules such as hexane or CCl₄, and the repulsive Interactions between extremely hydrophilic molecules such as poly(ethylene oxide) (PEO), when immersed in water, as well as the interactions between these molecules and water, have been examined from a surface thermodynamic viewpoint, taking the changes in surface free energy into account, as a function of temperature. It was found that attractive hydrophobic Interactions are not, as vas generally believed up to now, invariably entropic. Hydrophobic Interactions can be mainly enthalpic or mainly entropic, or more or less equal mixtures of both, depending on each individual case; however, all hydrophobic interactions are polar (in the sense of Lewis acid-base) in nature. Repulsive hydrophilic interactions are enthalpic, and also polar in nature. The interaction between hydrophobic solutes and water is mainly enthalpic, and is apolar in nature.     

MECHANICS AND THE EVOLUTION AND FUNCTIONAL MORPHOLOGY OF CONCHOSTRACAN CARAPACE MECHANICS AND THE EVOLUTION AND FUNCTIONAL MORPHOLOGY OF CONCHOSTRACAN CARAPACE

Conchostracans, with a laterally compressed body enclosed between two symmetric valves, live swimming in fresh or brackish water. The carapace valve has a number of growth bands with various sculptures. The general trend of sculptural evolution is from smooth to punctate-minute polygon-medium reticulation-large reticulation, while these punctate, polygonal and various reticulate patterns may separately develop into various radial ridges. The development of sculpture can be well explained by mechanical principle. Functional morphology of carapace is discussed in the light of mechanics in this paper.     

HYDROXYSTILBAZOLES AND HYDROXYAZAPHENANTHRENES: PHOTOCYCLIZATION AND FLUORESCENCE STUDIES

Abstract— As models for novel fluorescent probes, we have synthesized three isomeric hydroxystilbazole systems (4′-hydroxy-substituted 2-, 3-, and 4-stiIbazoles), examined their photocyclization-oxi-dation to four hydroxyazaphenanthrene systems, and made a preliminary study of their absorption and fluorescence spectra. All three stilbazoles can be prepared easily by addition of the isomeric picoline anions to 4-methoxybenzaldehyde, followed by dehydration and deprotection. Photocyclization proceeds efficiently, furnishing a single product isomer from each of the 2- and 4-stilbazole systems, and two isomeric azaphenanthrenes from the 3-stilbazole. The stilbazoles all have intense UV absorbance bands whose maxima depend upon solvent and pH; all three isomers have relatively similar spectra under neutral conditions and all three show a large red shift in base; in acid, however, the 2-and 4-stilbazole isomers show a greater red shift than the 3-stilbazole. The fluorescence of the stilbazoles is also solvent dependent, shifting to the red in more polar medium; red shifts are also observed in acid and base, but in acid, the 3-stilbazole shows a larger shift. The azaphenanthrene photocyclization products show absorbance spectra typical for quinolines and isoquinolines; their absorptivities are less than the stilbazoles, but their fluorescence is more intense. In general, the benzoquinolines have longer wavelength but weaker fluorescence than the benzoisoquinolines. Also, those isomers in which the resonance effects of the hydroxy and nitrogen groups can reinforce one another show longer wavelength emissions of greater intensity. All seven systems show dual fluorescence in water under neutral conditions, suggesting the emission from both non-ionized and ionized species in the excited state. In one case, the benzoisoquinoline system derived from 4′-hydroxy-4-stilbazole, an emission at 640 nm, observed in water over a wide pH range, is ascribed to a zwitterionic phototautomer. These stilbazoles, benzoquinolines and benzoisoquinolines may prove to be useful spectroscopic probes.