Synthesis and photo-activity of peptide nucleic acids containing an azobenzene unit

We prepared the azobenzene PNA unit and synthesized various PNAs containing an azobenzene unit by a typical tBoc method. Both the azobenzene PNA unit and PNA containing an azobenzene unit （N-PNA） showed reversible photoisomerization with UV and visible light irradiation. The hybridization of N-PNA with complementary DNA resulted in a considerable decrease of the photoisomerization rate constant of the azobenzene.     

蜜胺修饰的偶氮类凝胶因子的合成及其凝胶行为

设计合成了2个双蜜胺修饰的偶氮苯类小分子有机凝胶因子M-AZO-1和MAZO-2.M-AZO-1和M-AZO-2能在多种有机溶剂中形成稳定的凝胶.通过SEM观察凝胶聚集体结构发现,凝胶因子在不同溶剂中形成凝胶的微观形貌结构不同,在乙酸乙酯等极性溶剂中凝胶纤维直径较大,在甲苯和甲基环己烷等非极性溶剂中凝胶纤维直径较小.进一步研究了UV光照对凝胶行为的影响.M-AZO-1和M-AZO-2经365nm UV光照后仍可以形成凝胶,其凝胶聚集体结构变化不明显.     

具有光活性含偶氮苯基团的新型表面活性剂的合成和性质

把具有光反应性的偶氮苯引入到表面活性剂2-(2-乙基己基)琥珀酸酯磺酸盐(AOT)中,合成了一种具有光活性的含偶氮苯基团的表面活性剂(azo-AOT).采用紫外-可见光谱对其进行了分析,结果表明化合物结构中的偶氮苯基团的顺反式异构化易于通过光的辐射来控制.     

Formation and regulation of supramolecular chirality in organogel via addition of tartaric acid

A new 1,8-naphthalimide derivative was prepared in which the C-4 position was substituted by pyridin-4-ol.This derivative shows good gelation property that can gelate most of polar solvents.As an achiral molecule,helical fibre morphology was observed when the compound gelated acetone solvent.When 0.5 eq of D-tartaric acid or L-tartaric acid was added to the gel,the helical morphology was changed from left-handed to right-handed structure.This result was further proved by circular dichroism measurement.FT-IR experiment showed the formation of intermolecular H-bond between the gelator and tartaric acid.The photophysical properties of gelator had no difference before and after addition of tartaric acid;whereas the lamellar structure was varied by addition of tartaric acid.     

银掺杂多孔氧化钛光催化甲基橙降解反应条件的探究

利用溶胶-凝胶法结合光还原法制备Ag掺杂多孔TiO_2光催化剂,以甲基橙的降解效果为评价标准,考查了光照降解时间、光催化剂用量、甲基橙溶液初始浓度、溶液pH值对光催化剂催化降解甲基橙的影响。结果表明,本方法制备的光催化剂无论是在紫外光还是可见光下均具有优良的光催化性能:在浓度为10 mg/L的甲基橙溶液中,4 g/L光催化剂,紫外光照射80 min,甲基橙可实现100%完全降解;相同催化条件下,可见光照100 min,甲基橙完全降解;当反应溶液pH=2时,紫外光和可见光都可在20 min内实现甲基橙的完全降解。     

偶氮基团修饰的苝酰亚胺染料的合成及其光响应行为

以3,5二羟基苯甲醇为原料,经醚化、溴代反应得到3,5二（十二烷氧基）苄基溴,然后与4羟基4′硝基偶氮苯反应,再还原得到含氨基的偶氮化合物6,最后与3,4;9,10苝四甲酸二酐缩合得到新型偶氮-苝酰亚胺二元染料7。考察了紫外光光照时间及浓度等因素对偶氮-苝酰亚胺二元染料光学性能的影响,结果表明浓度越大,偶氮生色团由反式结构向顺式结构的转变速度越慢;对相转移法组装形成的聚集体形貌结构的研究表明,当甲醇与三氯甲烷体积比为7∶1或5∶1时,更易形成较规整的短棒;比较研究紫外光光照和未光照下快速溶剂扩散法组装形成的聚集体形貌结构发现,光照下制备的聚集体结构的规整性不及未光照下制备的;吸收光谱表明在光照下组装的聚集体分子间π*π堆积作用更弱,这是由于偶氮基团由反式结构向顺式结构的转变导致分子空间几何构型的变化,破坏了分子堆积的有序性,不利于低维功能材料的形成。     

二茂铁基偶氮苯甲酸的溶液光化学和电化学行为

合成了一种新型的具有光活性和氧化还原活性的两亲性分子—4-(11-二茂铁基正十一烷氧基)偶氮苯甲酸(FcAzCOOH), 并对用元素分析、核磁共振氢谱, 红外光谱对产物进行了确认与表征.紫外-可见(UV-Vis)吸收光谱研究表明FcAzCOOH在THF溶液中具有很好的光致异构行为. 循环伏安（CV）研究表明FcAzCOOH在DMF溶液中的电极过程为受扩散控制的可逆过程. 通过对不同紫外光照时长下FcAzCOOH溶液的循环伏安行为研究表明: 紫外光照对其溶液电化学行为几乎没有影响.     

单L-苯丙氨酸衍生物对乙醇/水混合溶剂的凝胶化研究

考察了单L-苯丙氨酸衍生物——L-3-[(3-硬脂胺酰基)-3-苯基-丙酰基]丁酸(SPAB)在乙醇/水混合溶剂中的凝胶行为,结果表明SPAB在乙醇/水的体积比从9:1到2:3的乙醇/水混合溶剂中能形成稳定的、热可逆的超分子凝胶。而在乙醇/水(V/V=1)溶液中的最低凝胶化浓度(MGC)低至1.2 mg/m L。凝胶的相转变温度(TGS)随凝胶因子浓度增加而升高。扫描电镜(SEM)观察到SPAB在乙醇/水混合溶剂中形成了相互交联的带状纤维聚集体。红外光谱(FTIR)结果表明SPAB分子中酰胺基团间的氢键、烷基的疏水作用以及水与SPAB分子中的羧基间的氢键是分子自组装的主要驱动力。     

金属水凝胶T-Ac-Zn的制备与表征

通过简单的实验方法合成了凝胶因子T-Ac,并利用核磁、质谱等实验方法确证其结构.一定条件下,凝胶因子T-Ac可以和Zn2+自组装形成白色不透明的金属水凝胶T-Ac-Zn,该凝胶具有良好的刺激响应性.为了探索成胶机理,通过各种实验方法对金属水凝胶T-Ac-Zn进行了表征.     

偶氮苯分子光致异构化的研究

偶氮苯类化合物分子在一定波长的光照射下会产生顺式反式的结构变化,利用东南大学分子逊实验室提出的薄膜实时演变分析技术和基于此技术所研制的系统对这一现象进行研究。我们发现甩膜法制备的异丁烯酸（２－对硝基偶氮苯）乙酯Ｐ１２薄膜在光照下的折射率的变化是由于偶氮苯分子的光致异构化造成的,用３６０ｎｍ光照使偶氮苯分子产生由反式到顺式的结构变化,再用４５０ｎｍ光照使偶氮苯分子产生由顺式到反式的结构变化。在薄膜实     

Electroantennogram responses of an invasive species fall webworm (Hyphantria cunea) to host volatile compounds

Electroantennogram responses of fall webworms(Hyphantria cunea) to 55 host volatile compounds were conducted.Results showed that male moths were more responsive to trans-2-hexenyl acetate,nonanal,hexanal,trans-2-hexenal,hexanol,isoamyl acetate,acetic acid cis-3-hexenyl ester,ethyl acetoacetate,citronellal and(+)-citronellal,and females were more responsive to hexanol,hexanal,acetophenone,isoamyl acetate,nonanal,trans-2-hexenal,acetic acid cis-3-hexenyl ester,citronellal,cis-3-hexen1-ol and trans-2-hexen-1-ol.Seven bioactive compounds were also selected for further dosage response experiments,and a positive correlation was found between the fall webworm and the tested compounds.A maximum dosage level of 1000 g was tested and found to elicit significantly higher activity from male moths compared with lower(1,10,100 g) concentrations.     

BiPO_4负载聚吡咯的纳米异质结制备及其光催化性能研究

通过水热法及自由基聚合反应制备了负载有聚吡咯的BiPO_4纳米异质结粉体材料,并通过紫外及可见光降解甲基蓝研究了其光催化性能.利用扫描电子显微镜(SEM)、热失重实验(TGA)、红外光谱(IR)、紫外可见(UV-Vis)、X射线衍射(XRD)等手段对产物的微观形貌、晶体结构与化学性质进行表征.制备的样品在进行0.5h的预吸附后,通过使用负载不同质量聚吡咯的复合材料分别在紫外及可见光照射下进行3h及6h的光催化降解实验,发现甲基蓝的最高去除率分别为78.2%和79.3%.     

金红石与针铁矿光催化材料结构与性能的关联

以TiCl4为钛源,针铁矿（α-FeOOH）为载体,采用水解沉淀法制备了金红石（TiO2）与α—FeOOH光催化材料．应用x射线衍射分析、扫描电子显微镜和透射电子显微镜对样品的晶相组成、形貌、微结构进行了表征．结果表明,制备温度对样品的晶相组成、形貌、颗粒大小和结构有明显的影响．随着制备温度升高．样品中α-FeOOH相的含量逐渐减少并最终消失,而金红石相TiO2的含量逐渐增加并最终全部金红石相TiO2;样品的形貌由棒状变为管状;复合材料的结构实现负载型→复合型→溶蚀复合型转变．应用紫外和模拟可见光谱对样品光性能进行了测试．样品对可见光的吸收得到了增强．在室温下以甲基橙为降解对象,分别在紫外光和模拟可见光照射下对样品光催化活性进行了评估．复合型和溶蚀复合型结构样品的活性均得到了不同程度的提高,而负载型结构样品的活性没有明显变化：在紫外及可见光照射下,样品对甲基橙的光催化降解效果较好,溶蚀复合型结构样品的活性最高．这说明样品的性能与结构有良好的关联性．     

水热法制备Eu3+掺杂TiO2光催化剂及其性能的研究

以硫酸钛为前驱物,采用水热法制备了系列Eu3+/TiO2复合纳米粉体,采用X射线衍射(XRD)、扫描电镜(SEM)、紫外-可见漫反射吸收光谱(UV-Vis)等测试手段对催化剂进行初步表征,并以甲基橙溶液作为光催化探针反应,测定其紫外光光催化活性.结果表明,实验均得到晶化较好的锐钛矿型TiO2纳米粉体,稀土Eu3+的掺入能有效抑制纳米颗粒的增长,并引起晶格膨胀;紫外-可见漫反射吸收峰有红移现象,即有一定的可见光响应;稀土Eu3+的掺杂能有效提高TiO2纳米粉体的光催化活性,最佳掺杂摩尔比为1%.     

A supramolecular gel based on an adenine symmetrically grafted Anderson-type polyoxometalate complex

An Anderson-type polyoxometalate was covalently decorated by using adenine on both sides.Through cation substitution,we obtained a new hybrid building block with long alkyl chains for supramolecular gels.According to the synergetic effect of hydrogen bonding of inter adenine units and van der Waals interaction of side alkyl chains,the DODA 3 [A-MnMo 6-A] gelator can stabilize solvent and self-assemble into fibrous structure,forming supramolecular gel.In addition,the reversible sol-gel transformation was achieved by controlling environmental temperature.Scanning electron microscopy,transmission electron microscopy and X-ray diffraction were used to characterize the gel morphology and structure.As a result,we proposed the possible mechanism of gel formation and sol-gel transformation.     

Preparation, characterization and photodegradation of methylene blue based on TiO2 microparticles modified with thiophene substituents

The new microparticles,2-formylthiophene(FT)/TiO2 and(E)-1,2-bis(5-formyl-2-thienyl) ethylene(EBFTE)/TiO2 were synthesized with a silane coupling agent.The prepared TiO2 composites were characterized using Ultraviolet-Vis absorption(UV-Vis),X-ray diffraction(XRD),scanning electron microscope(SEM) and thermogravimetric analyzer(TGA).Methylene blue was used as a model material to examine the photocatalytic activities of the prepared catalysts under both Ultraviolet-Vis(UV) and visible(Vis) light.The enhanced photocatalytic activities were observed in the presence of(FT)/TiO2 and EBFTE/TiO2 under Vis light.It suggests that FT or EBFTE plays a block or active role in the photodegradation mechanisms under UV and Vis light irradiation,respectively.     

Ferric perchlorate-promoted reaction of [60]fullerene with β-keto esters

The ferric perchlorate-promoted reaction of [60]fullerene (C60) with ethyl 2-methylacetoacetate generates fullerenyl hemiketal as a mixture of trans and cis isomers,while the reaction with ethyl acetoacetate gives a C 60-fused dihydrofuran derivative.A possible reaction mechanism for the formation of these products is proposed.     

Bionic titania coating carbon multi-layer material derived from natural leaf and its superior photocatalytic performance

Bionic titania coating carbon multi-layer material was fabricated by employing canna leaves as substrate and carbon precursor. Titania nanocrystals were assembled and coated on the natural films. The carbonation treatment under pure N_2 atmosphere yielded the ultrathin multi-film hybrid material. The carbon layer was coated with small anatase titania crystallite(8–10 nm) and possessed a highly specific surface area of 248.3 m~2 g~(-1). Examination using UV–visible spectrophotometer(UV–vis) showed that the band gap of the multi-layer material was reduced to 2.75 eV, and the hydrogen production by photocatalytic splitting of water under visible light irradiation was about 302 μmol g~(-1) after six hour.     

偶氮苯调控DNA解链的机理研究

采用半经典动力学模拟的方法研究了偶氮苯、2-甲基偶氮苯及2,6-二甲基偶氮苯3种分子的光致异构化反应,上述3种偶氮分子结构由反式变为顺式的时间顺序是偶氮苯2-甲基偶氮苯2,6-二甲基偶氮苯,说明光致异构化反应的活化能顺序是偶氮苯2-甲基偶氮苯2,6-二甲基偶氮苯。这就意味着2,6-二甲基偶氮苯发生光致异构化反应必须吸收足够高能量形成活化分子,从而克服过渡态能垒。较高的能量状态决定了分子在过渡态的热力学稳定性降低,因此反式的2,6-二甲基偶氮苯在过渡态更容易失活,形成顺式异构体。模拟结果解释了2,6-二甲基偶氮苯对DNA解链过程调控效率最高的实验现象。     

烷氧基偶氮苯-喹啉化合物的合成、表征及性能

以间苯二甲酸为原料,经多步反应合成了两种新型烷氧基偶氮苯-喹啉化合物5-[8-(丁氧基)喹啉-5-偶氮]-1,3-苯二甲酸二乙酯(5a)和5-[8-(辛氧基)喹啉-5-偶氮]-1,3-苯二甲酸二乙酯(5b),通过IR、UV-Vis、1 H NMR和MS等对其结构和性能进行了表征.利用吸收光谱和发射光谱研究了目标化合物的反-顺异构化和发光性能.目标化合物5a和5b(2.0×10-5 mol/L的DMF溶液),在365nm紫外光照射下,400nm处的偶氮苯-喹啉结构K带π-π*跃迁吸收峰及267nm处芳香环的B带π-π*跃迁吸收峰逐渐减弱,光照6min后达到光稳态.目标化合物5a和5b(2.0×10-5 mol/L的DMF溶液)均以311nm光激发,分别在420,418nm处发射蓝紫色荧光.