Dual Spectroscopic Responses of Pyridinium Hemicyanine Dyes to Anions

The absorption and fluorescence spectroscopic responses of three pyridinium hemicyanine dyes to anions F⁻, Cl⁻, Br⁻, I⁻, H₂PO₄⁻, HSO₄⁻ and OAc⁻ were investigated. At lower concentrations of OAc⁻ (less than 1 equiv.), both the absorption and the fluorescence intensities of 1 – 3 were more effectively changed than F⁻ at identical concentrations. At higher concentrations of OAc⁻ (more than 1 equiv.), the interaction was opposite for each compound. ¹H NMR results indicated the interaction between 1 , 2 or 3 and F⁻ proceeded through hydrogen bonding. The results showed that these dyes are promising to develop dual fluorescence and chromogenic chemosensors toward F⁻ and OAc⁻ according to the subtle difference in the affinity of F⁻ and OAc⁻.     

LB膜混合聚集体中极性基团相互作用对光学非线性的影响

通过紫外－可见吸收光谱、压力－面积等温线、二次谐波的测量，研究了不同活性分子混合聚集体的形成对ＬＢ膜光学性质的影响。分子极性基团间的相互作用，使激发态能量及平均偶极矩发生变化，导致ＬＢ膜的光学非线性明显地增强或减弱。     

2-取代吡啶半菁染料的无溶剂微波合成及光谱性质的理论研究

在微波促进无溶剂条件下, 由N-甲基-2-甲基吡啶碘盐与取代芳香醛在哌啶作用下合成了一系列2-取代的吡啶半菁染料, 产物结构由元素分析, ¹H NMR, MS, IR, UV得到确认. 该方法操作简便, 收率高. 在此基础上, 对N-甲 基-2-(p-N,N-二甲氨基-苯乙烯基)吡啶半菁染料的光谱性质进行了理论计算.     

Synthesis and Properties of Novel Hemicyanine Dye-β-Cyclodextrin

A series of novel hemicyanine dye-β-cyclodextrin compounds： mono-6-deoxy-β-cyclodextrin-6-[p-（p-substituted styryl）pyridium] p-totylfulfonates were synthesized by the condensation of mono-6-deoxy-β- cyclodextrin-6-（p-methyl pyridinium） p-toluenesulfonate with （un）substituted benzaldehydes. Their structures were established by 1^H NMR, IR, UV-Vis and elemental analysis. The absorption and fluorescence properties of the novel compounds were measured in solution and the photostability of a selected hemicyanine dye-β-cyclodextrin compound was also investigated.     

新型含羧戊基不对称五甲川菁染料的合成及蛋白标记

以磺酸基苯肼和7-甲基-8-氧代壬酸为原料合成了2,3-二甲基-3-羧戊基-3H-吲哚-5-磺酸;以2,3,3-三甲基-3H-吲哚-5-磺酸和1,3-丙磺酸内酯为原料合成了1-磺酸丙基-2,3,3-三甲基-3H-吲哚-5-磺酸;然后通过半菁合成法合成了一种新型水溶性不对称五甲川吲哚菁染料(Cy5)。产物经C18反相硅胶柱分离,收率57%,其结构经1H NMR、HRMS进行确证。并检测了目标化合物的光谱性质,初步探讨了其在生物标记方面的应用。染料具有良好的水溶性和光稳定性,水溶液的最大紫外吸收波长和最大荧光发射波长分别为646和666 nm,荧光量子产率为0.2,用n(活化菁染料)∶n(牛血清蛋白)=2∶1标记蛋白,D/P值为1.56。     

TiO2纳米晶电极上半菁衍生物分子设计中空间位阻效应的研究

设计合成了具有不同空间位阻的吡啶盐类和喹啉盐类半菁染料(E)-N-(4—磺酸 根丙基)-4-[2-4（4-N，N-二乙基氨基苯基）乙烯基]吡啶鎓盐（EPS），（E）-N-(4- 磺酸根丁基）-4-[2-(4-N,N-二乙氨基苯基）乙烯基]吡啶鎓盐（EPS4）和（E） -N-（4-磺酸根丁基）-4-[2-（4-N，N-二乙基氨基苯基）喹啉鎓盐（EQS4），研究了它们 的光物理性质，并将它们用作TiO2纳米晶电极的光敏化剂引入光电化学电池中。 研究发现:对于吡啶类半菁染料而言，无论是以三个亚甲基或是以四个亚甲基来连接 吸附基团RSO3^-和发色团时，单个的EPS和EPS4分子的光电响应行为一致．但是由于 以三个亚甲基来连接时，与EPS4相比，染料EPS的空间位阻相对较小，有利于其在 多孔膜上的吸附，最终结果是染料EPS对TiO2纳米晶电极的敏化作用好于EPS4．以喹啉 环为受电子基团的染料EQS4与同样含有四个亚甲基的以吡啶环为受电 子基团的EPS4相比，单个EQS4分子的光电响应行为虽然好于EPS4分子，但由于 EQS4分子间的空间位阻较大，影响了它在多孔电极上的吸附，致使其敏化的太阳能 电池的总光电转换效率有所下降．     

半花菁衍生物分子第一超极化率频率色散效应的理论研究

采用含时耦合微扰(TDHF)和多态求和(SOS)方法计算了半花菁衍生物分子生色团4-N,N-dimethylami-no-4′-N′-methylstilbazolium(DAS)的第一超极化率频率色散效应。采用组态相关(INDO/CI)方法计算了分子的前线轨道性质。计算结果表明半花菁衍生物分子最大吸收波长约为480nm,与实验结果十分吻合;第一激发态对体系非线性光学性质起决定作用。在红外波段(800~2500nm),随着基频光频率的增大,二次谐波β(-2ω;ω,ω)和电光效应β(-ω;ω,0)都随之增大,但是β(-2ω;ω,ω)增加的幅度要大于β(-ω;ω,0)。在远红外区β(-2ω;ω,ω)的色散曲线变化比较平缓,到了近红外区(λ<1300nm)共振增强效应逐渐明显。基频光波长为1064nm时,β(-2ω;ω,ω)的含时耦合微扰计算值约为(380±5)×10-30esu。在较高频率时,采用多态求和方法计算应考虑其他态的贡献。此外,还讨论了基组效应对含时耦合微扰计算的影响。     

LB膜中聚集体的时间分辨荧光研究

利用吸收，稳态和时间分辨荧光方法研究了苯腙（ＰＤ）和半花菁（ＤＡＥＰ）分子在Ｚ型ＬＢ多层膜中的聚集性质，苯腙和半花菁吸收光谱的红移和兰移，说明它们分别以Ｊ和Ｈ型聚集体形式存在于ＬＢ膜中，苯腙和半花菁ＬＢ膜的荧光发射带分别在５６０ｎｍ和５８４ｎｍ处，亦分别对于它们溶液的荧光谱呈示出红移和兰移的特征，它们的荧光衰减曲线能很好地用双指数模拟拟合，在苯腙和半花菁ＬＢ多层膜中主要存在着荧光寿命分别在ｎｓ和１     

New heterobicationic hemicyanine dyes: Synthesis,spectroscopic properties,and photoinitiating ability

This article describes the synthesis, spectroscopic properties, and free‐radical photoinitiation ability of new heterobicationic hemicyanine dyes. A new synthetic strategy for the preparation of unsymmetrical cyanine dyes has been developed, based on 2‐methylbenzothiazole derivative quaternization by 3‐pyridinium‐1‐bromopropane bromide and subsequent condensation of the resulting product with p‐(N,N‐dimethylamino)benzaldehyde. The tested dyes possess in one molecule two quaternary nitrogen atoms; that is, they are heterobicationic in nature. Novel hemicyanine dyes have been tested as visible‐light photoinitiators of vinyl monomer polymerization. Heterobicationic hemicyanine dyes paired with n‐butyltriphenylborate anions are very efficient photoinitiators of the free‐radical polymerization of trimethylolpropane triacrylate when irradiated with the visible emission of an argon‐ion laser. The photoinitiating abilities of the novel photoredox pairs are compared with the photoinitiation properties of their monocationic equivalent {3‐methyl‐2‐[4‐(N,N‐dimethylamino)styryl]benzothiazolium n‐butyltriphenylborate} as well as a Rose Bengal derivative (a typical triplet‐state photoinitiator). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6345–6359, 2006