软模板印刷法制备超疏水性聚苯乙烯膜

首次利用软模板印刷的方法,以微米-亚微米-纳米复合结构的PDMS为软模板,在平滑聚苯乙烯表面上成功制备了同样具有微米-亚微米-纳米复合结构的超疏水表面,该表面与水的接触角高达161.2º。软模板印刷方法可以用在其它热塑性聚合物如聚丙烯、聚甲基丙烯酸甲酯和聚碳酸酯等材料上,是一种简单有效地制备超疏水性表面的方法。     

ZnO纳米粒子结构对光电量子限域特性的影响

Zn O作为一种宽禁带 (3 .3 6e V)高激子结合能 (60 me V)的半导体材料已引起人们的关注 .Zn O纳米粒子的比表面积较大 ,表面活性较高 ,对周围环境敏感 ,使其成为传感器制作中最有前途的材料[1] ,还在太阳能转换[2 ] 、发光材料[3] 、半导体表面修饰与敏化[4 ] 、纳米电子学以及分子电子学器件[5] 等领域显示出广阔的应用前景 .制约这些应用的关键是 Zn O纳米粒子表面和界面的电子结构和电荷转移行为 ,但有关此方面的报道较少 .本文用溶胶 -凝胶法制备了不同粒径的 Zn O纳米粒子 ,应用表面光电压谱 (SPS)和场诱导表面光电压谱 (FISPS…     

手性模板合成CdS纳米棒

由于纳米材料具有量子尺寸效应及大的比表面积等性质而使其在电子学[1]、光学[2]、催化[3]和陶瓷[4]等领域显示出诱人的应用前景. 近年来纳米材料的制备及纳米技术发展迅速, 特别是具有特殊光电活性的新型无机纳米材料的制备已引起人们的普遍关注. 现在合成纳米材料的方法主要包括反相胶束法[5]、 LB膜法[6]、嵌段共聚物法[7]和模板合成法[8]. 其中模板合成技术不仅可以通过设计新型的模板分子, 还可通过模板分子的不同自组装行为来调控纳米材料的尺寸和形貌. Stupp等[9]曾利用溶致液晶的六方中间相作为模板, 在其纳米孔隙中成功地合成了具有六方排列超晶格纳米结构的材料. 本文以双亲性丙氨酸衍生物为模板, 在不同的化学微环境下合成了结构不同的CdS纳米棒.     

相反转乳化技术制备环氧树脂交联多孔微球

多孔微球在分离吸附、催化、涂料印刷等多方面具有潜在应用价值 .最近研究表明 ,当微孔孔径在 2 0 0～ 80 0ｎｍ范围时 ,由于强烈的光散射作用 ,多孔微球可以作为遮光剂使用[1] .Ｏｋｕｂｏ等用酸碱逐步处理法制备了一些共聚物的亚微米级多孔球[2～ 4] .Ｏｋｕｂｏ又用动态溶胀种子聚合法制备了微米级的聚合物微球 ,用类似的方法得到了多孔结构[5,6] .但这种方法涉及了许多烦琐过程并且产生了很多副产物需要处理 ,使得其费时费力而且成本相当高 .Ｓｃｈｌａｒｂ等发展了一种新的制备方法 ,在乳液聚合过程中引入有机溶剂 ,在实验后期除掉有机…     

基于分子间π-π相互作用形成的吖啶荧光化合物超分子结构及其性能研究

合成了10-甲基-1,2-苯并吖啶（10-Methyl-benzo[1,2]acridine,MBA）,用X射线单晶衍射方法获得了其单晶结构,结构分析结果表明,在MBA晶体中,由于存在分子间π-π相互作用,形成了一维无限伸展的分子柱,用MBA制备了微米晶体,通过调控反应物的浓度可以获得长方和线状的微米晶体,用荧光显微镜考察了微米晶体的形貌,研究了MBA的紫外吸收和荧光发射光谱性质,实验结果表明,MBA是一种具有蓝光发射特点的有机分子。     

DNA与苯胺红T的相互作用与荧光定量检测

荧光染料作为分子探针用于核酸的定量测定和构象分析一直备受关注 [1] .已有数十种荧光染料被应用[2 ,3 ] ,如溴化乙锭早期常用作 DNA探针[4 ,5] ,因其有很强的致癌性 ,目前已很少采用 ,而那些无毒性或含有可被衍生的活性基团的探针分子越来越受到青睐 [6～ 8] .苯胺红 T(ST)是一种阳离子型荧光染料 ,它既可很容易地与 DNA双螺旋结构发生插入作用 ,又可由带正电的吩嗪环与 DNA上带负电的磷酸基发生强烈的静电吸附作用 ,还可利用其氨基与 DNA或其它生物分子进行交联 .He等 [9] 曾研究了它与小牛胸腺 DNA之间的作用 ,得到的结合位点数…     

纳米银的电化学合成

纳米颗粒因具有量子尺寸效应、表面效应和宏观量子隧道效应等不同于晶态体材料和单个分子的固有特性 ,显示出体材料不具备的导电特性、光电特性、光催化能力及随粒径变化的吸收或发射光谱 ,已被用于各种发光与显示装置[1] .其制备的化学方法主要有溶胶 -凝胶法、微乳法、化学沉淀法和醇解法等 [2 ] .近年来 ,新发展出一种电化学合成纳米粒子的方法 ,如 Braun等 [3]利用 DNA模板电化学合成了银纳米线 ,Yu等[4 ] 用电化学合成了金纳米棒 ,Zhu等[5] 利用超声电化学合成了半导体 Pb Se纳米粒子 ,Amigo等 [6 ]用电化学方法合成了 Fe-Sr氧化…     

硅表面有机单层膜 :微印章、微加工与微阵列

总结了作者的实验室在将有机物结合到硅表面方面的研究进展.发现并发展了将有机单层膜组装到硅、氧化硅和相关材料表面的新方法.这些方法简单、可重复，并可得到物理、化学性能良好的致密单层膜.这些单层膜在许多方面有令人鼓舞的应用，包括（a）应用于软印刷术，特别是微接触印章法; （b）用作硅的微加工（微机电系统，MEMS）的单层膜润滑剂; （c）用作DNA和蛋白质微阵列功能分子固定的基底.     

1,3-二苯基-2-吡唑啉纳米带的制备及其光波导性质

以1,3-二苯基-2-吡唑啉(DP)为目标化合物, 利用再沉淀方法, 以混合溶剂作为不良溶剂, 制备了形貌均一、宽度约2 μm、厚度200 nm和长度数十微米的一维纳米带状结构. 选区电子衍射结果证实, DP分子在纳米带中因为强的分子间π-π相互作用而沿着晶体[100]方向优势生长. 稳态光谱结果表明, DP纳米带具有不同于分子和体相材料的介观特性. 由于J-聚体在DP纳米带中优势形成, 其480 nm的发射峰与分子和体相材料相比分别红移了30和20 nm. 利用扫描近场光学显微镜进一步发现, 一维DP纳米带类似于天然的亚波长尺度谐振腔, 紫外激发DP分子发射的荧光被限域在DP纳米带中, 沿一维方向传导并在两端耦合输出.     

DNA的导电性浅析

DNA是构成生命基础的最重要分子,DNA是否导电以及怎样导电,关系到我们对生命信号的传递、和对生命和生命现象的深入理解和揭示,以及可编程DNA分子电子学的发展,国际科技界一直高度关注,近二十年来也一直是研究的热点和难点.然而,DNA是一个复杂的体系,其导电性问题仍然不清楚,备受争议.本综述中,我们简述了DNA导电性问题的研究历史,分析了DNA导电性问题争议的主要原因,总结了DNA导电性研究中存在的主要问题,其主要归因于测量方法的多样性和DNA分子的复杂性.最后,对DNA导电性研究的未来发展方向进行了展望,DNA导电性在生命信号传递、生物传感器、分子电子学等领域具有巨大的应用潜力,其研究也将为生物科学和电子学的融合提供新思路.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.