Investigation on the Crystal Structure of Substituted Pyridine Based Organic Salt as the Low Molecular Weight Gelator

In order to define the chemical conformation of gelator,para-hydroxy pyridinium salt of 1,2,4,5-benzene tetracarboxylic acid(defined as G1),four model compounds were prepared from para-,meta-,ortho-phthalic acid with 4-hydroxy pyridine(PHP),and 1,2,4,5-benzene tetracarboxylic acid(BTA) with 4-pyridylcarbinol(PCB),and their 1H NMR spectra were investigated.The single crystal of G1 obtained directly from gelling solvent was measured,which displayed complicated hydrogen-bonded networks arising from the supramolecular synthons and other weak interactions between H2O and the components.The powder X-ray diffraction(XRPD) experiments were also carried out to understand the relationship between molecular packing of the bulk crystal and the gelation behavior.     

手性有机-无机杂化氧化硅纳米管的制备

依照文献以L-苯甘氨酸为手性源合成了一个手性阴离子两亲小分子化合物.利用圆二色谱表征了该化合物水中的自组装行为.通过溶胶-凝胶复制法,以该手性两亲小分子化合物和结构助剂的组装体为模板制备了右手螺旋有机-无机杂化氧化硅纳米管.圆二色谱表征结果表明,4,4′-亚联苯基氧化硅中的联苯基团呈手性堆积.     

Tetrathiafulvalene (TTF)-based gelators:Stimuli responsive gels and conducting nanostructures

Tetrathiafulvalene (TTF) and its derivatives have been intensively investigated for conducting materials for more than 30 years.As π-electron donors,TTF and its derivatives can be reversibly transformed into the respective TTF.+ and TTF2+.Due to its reversible feature,the TTF unit has been widely employed as the building block for switchable systems.In recent years studies of conducting nanostructures of TTF derivatives have received more and more attention.One simple way to prepare nano-structures is throu...     

π-共轭三苯基苯衍生物的合成及其胶凝性能

合成了一系列三单脂肪链具有盘状结构的三苯基苯衍生物并研究了其在有机溶剂中自组装行为. 结果表明, 该系列衍生物在多种低极性有机溶剂中可以形成稳定的凝胶, 利用小角X射线衍射实验和扫描电子显微镜技术观察到干凝胶的分子排列具有层状结构, 形成纤维状和片层状聚集, 紫外-可见吸收光谱和红外光谱结果表明分子间氢键和π-π共轭堆积效应是形成自组装凝胶的主要驱动力. 在形成凝胶过程中, 凝胶剂分子在溶液中通过盘状中心的π-π共轭堆积效应和酰胺键的分子间氢键作用自组装成层状结构, 层状结构进一步组装形成纤维状和片层状聚集体, 最终形成三维网状结构阻碍溶剂流动形成凝胶.     

四(十二烷基)氯化铵基小分子凝胶电解质染料敏化太阳电池

采用小分子胶凝剂四（十二烷基）氯化铵胶凝3-甲氧基丙腈基液体电解质制备了凝胶电解质，并组装成准固态染料敏化太阳电池．差示扫描量热测试结果表明，凝胶电解质的溶液-凝胶转变温度（TSG）为74℃．分析了凝胶电解质中I3^-／I^-电对的表观扩散系数低于液体电解质的原因，同时结合电化学阻抗技术考察了电池内部二氧化钛多孔薄膜电极／电解质界面处的暗反应，分析了凝胶化对电池光伏性能的影响．老化实验结果表明，凝胶电池的稳定性明显优于液体电池．     

Surface‐enhanced Raman scattering on colloid gels originated from low molecular weight gelator

Surface‐enhanced Raman scattering (SERS) on silver and gold colloid gels formed by a low molecular weight organic gelator, bis‐(S‐phenylalanine) oxalyl amide, was obtained. Strong Raman signals dominate in the SERS spectra of hydrogels containing silver nanoparticles prepared by citrate and borohydride reduction methods, whereas broad bands of low intensity are detected in the spectra of gold colloid gels. Resemblance between Raman spectrum of the crystalline substance and the SERS spectra of the silver nanoparticle–hydrogel composites implies the electromagnetic nature of the signal enhancement. A change in Raman intensity of the benzene and amide II bands caused by an increase in temperature and concentration indicates that the gelling molecules are strongly attached through the benzene moieties to the metal nanoparticles while participating in gel formation by intermolecular hydrogen bonding between the adjacent oxalyl amide groups. Transmission electron microscopy reveals a dense gel structure in the close vicinity of the enhancing metal particles for both silver colloid gels. Copyright © 2008 John Wiley & Sons, Ltd.     

新型甘露醇基凝油剂的制备及性能研究

通过甘露醇和环己酮的缩酮反应,合成了具有相选择性的新型糖基凝油剂-环己酮缩甘露醇。考察了反应时间、催化剂用量、分子筛用量、底物配比等多个因素对产物产率的影响。结果表明,分子筛用量为12g、催化剂用量为0.8g、环己酮与甘露醇摩尔比为6.2∶1的条件下反应1h,产率为52%。对所制备的环己酮缩甘露醇的凝油能力测试表明,它可以凝固汽油、硅油等多种油类,柴油、汽油和硅油凝固的最小浓度分别为0.74(wt)%、2.70(wt)%和0.39(wt)%。     

Selective sensing of Hg2+ via sol–gel transformation of a cholesterol-based compound

A cholesterol-based dithioacetal functionalised compound 1 has been designed, synthesised and successfully applied for the selective detection of Hg²⁺ ion. The specific Hg²⁺-induced deprotection of the thioacetal functionality of 1 resulted in sol-to-gel transition in DMF-H₂O (1:1, v/v) via the formation of precursor aldehyde 3. This Hg²⁺-prompted rapid sol to gel conversion is insensitive to the nature of Hg²⁺-salt. In the study, other metal ions did not show any change. To the best of our knowledge, this is a first time report of a chemodosimeter that functions as a selective ‘naked-eye’ Hg²⁺-detector by showing in situ sol-to-gel conversion.     

可聚合凝胶因子的合成及其有机凝胶热力学研究

合成了一种可聚合凝胶因子（Gelator)4，4’-二（α－甲基丙烯酰氧基－1， 3－亚乙氧基羰基丙酰氨基）二苯甲烷（BMDM）。BMDM能在二苯醚、甲苯、二甲苯 、氯苯等含苯环的低极性溶剂中形成热可逆的物理凝胶，而在二甲基甲酰胺、乙醇 和二氯甲烷等强极性溶剂中则易溶解，在乙醚、石油醚等非极性溶剂中不可溶解。 FT－IR和DSC研究该凝胶因子在二苯醚中形成的凝胶，发现该凝胶因子是通过氢键 等次价键力相互作用而聚集、自我组装形成凝胶的。利用溶胶－凝胶相转变和DSC 数据，研究了该有机凝胶的热力学参数和性质，BMDM在二苯醚中形成的凝胶聚集体 间的范德华弱相互作用焓为ΔH=0.8kJ·mol^-1，凝胶－溶胶相转变热焓为ΔH=22. 3kJ·mol^-1。     

Effect of alcohol-water exchange and surface scanning on nanobubbles and the attraction between hydrophobic surfaces

4-(4′-Butoxyphenyl)phenyl-β-O-d-glucoside was synthesized as a low-molecular-mass gelator. It was able to immobilize a variety of aqueous and organic solvents in large amounts through the formation of three-dimensional self-assembled fibrillar networks. The morphologies of the aggregates depended on the nature of solvent where they were formed. Planar ribbons were observed in water, while helical ribbons were dominant in toluene and sheets in CHCl₃. The xerogel from water exhibited a lamellar structure with a d-spacing of 2.45 nm as demonstrated by 1D-WAXD, indicating a bilayer structure interdigitated with butoxy tails, whereas the xerogel from CHCl₃ or toluene yielded a lamellar structure with a d-spacing of 3.05 nm, implying a bilayer structure interdigitated with glycosyl heads. Increasing the content of 1,4-dioxane in water caused a gradual transformation from planar to twisted ribbons and then tubes.