甲基化的β-环糊精与十六烷基三甲基溴化胺的相互作用

环糊精与表面活性剂的相互作用已有许多研究,但多局限于β－环糊精（β－CD）,而修饰的β－环糊精与表面活性剂的相互作用研究较少[1－3]．分子内扭转电荷转移（TICT）激发态对介质极性高度敏感性,已成功地用于探针环糊精与表面活性剂的相互作用[4]．研究表明,β－CD能够诱     

环己烷中苯甲酰苯胺的双重荧光--分子内电荷转移的直接光谱证据

自从O Connell等［1］报道苯甲酰苯胺(BA)在EPA玻璃体中异常的长波长荧光发射特性以来, 已有众多学者尝试解释该"异常"荧光的发射态性质［2～12］. Kasha等［2～7］认为长波长荧光是质子转移(PT)和电荷转移(CT)两种激发态发射的叠加, 而Azumaya等［8］则认为发射态只包含分子内扭转电荷转移(TICT)态. 应该指出的是, 在上述研究中, 电荷转移态的指认并无有力的实验事实, 而主要是依据与具有CT双重荧光的对二甲氨基苯甲氰［13,14］的类比. 显然, 有关苯甲酰苯胺的长波长荧光发射态的准确性质仍待实验阐明     

重氮树脂型聚电解质复合物与SDS相互作用研究

由于聚电解质与表面活性剂的相互作用具有很多特别的性质而倍受关注［１～１０］,但具有感光性的重氮树脂作为正离子聚电解质与表面活性剂相互作用尚未见报道．本文研究了重氮树脂（ＤＲ）与聚苯乙烯磺酸钠（ＰＳＳ）形成的聚电解复合物（ＤＲ－ＰＳＳ）与十二烷基硫酸钠...     

β-环糊精和十六烷基三甲基溴化铵混合介质中对二甲氨基苯甲醛的分子内扭转电荷转移

分子内扭转电荷转移(TICT)荧光体通常具有典型的双重荧光发射,其中短波荧光带(b带)对应正常激发态,长波荧光带(a带)对应TICT激发态。由于TICT态涉及一个完整的电荷转移,具有较大的偶极矩,其荧光发射体现出明显的溶剂极性相关性,因此适于作为一种新的荧光探针。前文已报道用对二甲氨基苯甲醛(DMABA)的TICT荧光性质研究β-环糊精(β-CD)和胶束的微环境效应。本文利用DMABA的TICT荧光性质研究了β-CD和十六烷基三甲基溴化铵(CTMAB)混合介质的性质,旨在阐明二者相互作用的特征。     

水溶液中的分子内扭转电荷转移：——阴阳离子胶束中对二甲…

在阳离子表面活性剂ＣＴＭＡＢ水溶液中，对二甲氨基苯甲酸（ＤＭＡＢＯＡ）的分子内扭转电荷转移（ＴＩＣＴ）荧光带随着胶束的形成而显著蓝移，同时伴随着ＴＩＣＴ荧光与正常荧光带强度比Ｉａ／Ｉｂ和总荧光强度Ｉｆ的增大；而阴离子表面活性剂ＳＬＳ胶束的形成并未引起ＴＩＣＴ荧光带位置和Ｉａ／Ｉｂ的变化，仅使Ｉｆ提高（较在ＣＴＭＡＢ胶束中的小）。实验发现的胶速疏水核中的ＴＩＣＴ行为与纯有机溶剂中不同，ＤＭＡＢＯＡ与     

C_(60)与含受电子生色基团聚合物的电荷转移现象

Ｃ６０与含受电子生色基团聚合物的电荷转移现象邱健姚光庆周锡煌李福绵（北京大学化学与分子工程学院北京１００８７１）关键词Ｃ６０，聚［Ｎ （４ 氰基苯基）丙烯酰胺］，电荷转移现象，荧光光谱随着对球壳烯性质的深入认识，球壳烯与电子给、受体的电荷转移现象日...     

荧光探针法测定甜菜碱cmc的研究

荧光探针法测定甜菜碱ｃｍｃ的研究任学贞，李干佐，王弘立，翟立民，隋卫平，徐欣艳（山东大学化学系，济南，２５０１００）关键词甜菜碱，芘，临界胶束浓度Ｅｋｗａｌｌ等［１］发现，表面活性剂的溶液能够增溶多环芳烃并发射较强的荧光．在常用的测定表面活性剂临界胶...     

添加剂对十二烷基磺酸钠溶液性质影响的研究

添加剂对十二烷基磺酸钠溶液性质影响的研究＊鲁润华郝京诚汪汉卿（中国科学院兰州化学物理研究所兰州７３００００）关键词表面张力电导添加剂Ａｓ中图分类号Ｏ５５２．４添加剂对表面活性剂溶液物理化学性质影响的研究是人们极感兴趣的研究内容［１］，因为表面活性剂实...     

α- 萘氧乙酸无保护流体室温磷光的重原子效应及有机溶剂的影响

萘氧乙酸（ＮＯＡ）是一类植物生长调节剂．对ＮＯＡ在β－环糊精（β－ＣＤ）保护下的室温磷光（ＲＴＰ）性质［１］和荧光性质［２］研究已有报道,但无保护性介质存在下的ＲＴＰ性质研究尚未见报道．我们在研究丹磺酰氯及其衍生物的无保护流体室温磷光（ＮＰ－ＲＴＰ）...     

表面活性剂对共轭聚合物荧光性质及电荷转移的影响

探讨了表面活性剂存在下, 水溶性阴离子共轭聚合物聚[5-甲氧基-2-(3-磺酰化丙氧基)-1,4-苯撑乙烯](简写为MPS-PPV)的微环境变化对荧光性质及电荷转移的影响. 结果表明, 阳离子表面活性剂及非离子表面活性剂使MPS-PPV荧光增强, 阴离子表面活性剂使其荧光先增强后减弱; 在MPS-PPV/表面活性剂体系中加入电子接受体Pd^2＋, 发现非离子表面活性剂体系的荧光猝灭效率提高, 阴离子及阳离子表面活性剂体系荧光猝灭效率下降. 此研究对研制基于阴离子共聚物的新型生物化学传感器具有一定的指导意义.     

核电胶束中分子内扭转电荷转移的醇效应

胶束中的分子内扭转电荷转移（TICT）研究可在更近层次上模拟叶绿体的光合作用的原初过程［‘，’］．因J已考察外加物对胶束中TICT的影响对于人。调节植物的光合作用以至植物的生长均有潜在的指导意义．显然了解外加物对胶束中uCT的影响情况并阐明其影响途径是。作的两个重要环节．这类。作迄今尚少见报导．前文问我们曾考察了无机盐对十六烷基三甲基溪化接（CTMAB）胶束中对二甲胺基苯甲酸（DMABOA）的TICT的影响，从胶束界面反离子结合这一角度出发探讨了盐效应的本质．本文将在此基础上利用TICT的rt重荧光（dualfluorescenc…     

水溶液中的分子内扭转电荷转移──阴阳离子胶束中对二甲基氨基苯甲酸分子内扭转电荷转移的比较研究

在阳离子表面活性剂CTMAB水溶液中,对二甲氨基苯甲酸(DMABOA)的分子内扭转电荷转移(TICT)荧光带随着胶束的形成而显着蓝移,同时伴随着TICT荧光带与正常荧光带强度比I_a/I_b和总荧光强度I_f的增大;而阴离子表面活性剂SLS胶束的形成并未引起TICT荧光带位置和I_a/I_b的变化,仅使I_f提高(较在CTMAB胶束中的小).实验发现在胶束疏水核中的TICT行为与纯有机溶剂中不同,DMABOA与CTMAB胶束的疏水相互作用和静电作用是协同的。     

分子内扭转电荷转移的新荧光探针的研究

选用对二乙氨基苯甲酸钠(SDEAB)和对二甲氨基苯甲酸钠(SDMAB)作为分子内扭转电荷转移(TICT)荧光探针, 表征了甲基修饰化所引起的β-CD空腔微环境的变化, 得出环糊精的非极性空腔有利于对二烷氨基苯甲酸型分子的TICT态形成的结论。以甲醇的测定为例, 展示了分子内扭转电荷转移作为荧光探针的分析应用。     

Intramolecular charge transfer at reverse micelle-water pool interface: p-N,N-dimethylaminobenzoic acid in AOT/cyclohexane/water reverse micelle

Photoinduced intramolecular charge transfer (ICT) of p-N,N-dimethylaminobenzoic acid (DMABOA) in AOT/cyclohexane/H2O reverse micelle was investigated and compared with that in CTAB/1-heptanol/H2O reverse micelle. It is proposed that the DMABOA molecule exists at the AOT reverse micelle water pool interface with its carboxylic group heading toward the water pool while the dimethylaminophenyl moiety buried in the micellar phase. Dual fluorescence of DMABOA that is indicative of the ICT reaction in the excited state was observed over the investigated water pool size, W of 3-17, in the AOT reverse micelle. The ICT emission of DMABOA in the AOT reverse micelle-water pool interface was found to be much weaker than that in the CTAB reverse micelle-water pool interface, and was attributed to the parallel direction of the electric field at the AOT reverse micelle-water pool interface to the charge transfer.     

分子内扭转电荷转移的胶束效应

研究了水溶液中对二甲氨基苯甲(DMABA)分子内扭转电荷转移(TICT)的胶束效应.胶束能促进DMABA的TICT过程,并导致DMABA的总荧光量子产率提高和TICT荧光峰的显著蓝移,DMABA的TICT荧光强度与正常荧光带的强度之比与DMABA的浓度之间有线性关系,胶束存在时该直线的斜率提高,认为DMABA的TICT激发态涉及两个DMABA分子,并且影响DMABA的TICT激发态相对布居的主要因素是其与相应的三重态和基态的能隙.讨论了DMABA的TICT激发态的可能结构及胶束效应的本质.     

Intriguing H-aggregate and H-dimer formation of coumarin-481 dye in aqueous solution as evidenced from photophysical studies

Photophysical properties of coumarin-481 (C481) dye in aqueous solution show intriguing presence of multiple emitting species. Concentration and wavelength dependent fluorescence decays and time-resolved emission spectra and area-normalized emission spectra suggest the coexistence of dye monomers, dimers, and higher aggregates (mostly trimers) in the solution. Because of the efficient intramolecular charge transfer (ICT) state to twisted intramolecular charge transfer (TICT) state conversion, the dye monomers show very short fluorescence lifetime of ~0.2 ns. Fluorescence lifetimes of dimers (~4.1 ns) and higher aggregates (~1.4 ns) are relatively longer due to steric constrain toward ICT to TICT conversion. Observed results indicate that the emission spectra of the aggregates are substantially blue-shifted compared to monomers, suggesting H-aggregation of the dye in the solution. Temperature-dependent fluorescence decays in water and time-resolved fluorescence results in water-acetonitrile solvent mixtures are also in support of the dye aggregation in the solution. Though dynamic light scattering studies could not recognize the dye aggregates in the solution due to their small size and low concentration, fluorescence up-conversion measurements show a relatively higher decay tail in water than in water-acetonitrile solvent mixture, in agreement with higher dye aggregation in aqueous solution. Time-resolved fluorescence results with structurally related non-TICT dyes, especially those of coumarin-153 dye, are also in accordance with the aggregation behavior of these dyes in aqueous solution. To the best of our knowledge, this is the first report on the aggregation of coumarin dyes in aqueous solution. Present results are important because coumarin dyes are widely used as fluorescent probes in various microheterogeneous systems where water is always a solvent component, and the dye aggregation in these systems, if overlooked, can easily lead to a misinterpretation of the observed results.     

氧鎓盐分子在受限制体系中的电荷转移和发光行为

2,4,6-三芳基氧盐是一类类似于三苯甲烷染料的化合物^[1].其结构中存在两种跃迁矩,分别对应于分子的X-轴方向(2,6-位取代基)和Y-轴方向(4-位取代基).因此,2,4,6-三芳基氧盐的吸收光谱中存在着两个较具特征的吸收峰^[2].     

Local viscosity analysis of triblock copolymer micelle with cyanine dyes as a fluorescent probe

The local viscosity of Pluronic F127 triblock copolymer micelles in water was determined with cyanine dyes as fluorescent probes. These dyes show very weak fluorescence at a low temperature, but show enhanced fluorescence at a temperature higher than the critical micellization temperature (T(cm)). This is because a viscous environment within the micelle suppresses the formation of a nonradiative twisted intramolecular charge transfer (TICT) excited state of the dyes. The good correlation between the fluorescence quantum yields of the dyes and the viscosity and the temperature of the media allows a determination of local viscosity of micelle based on the fluorescence quantum yields. The local viscosity of both core and corona regions of micelles increases at >T(cm) and shows a maximum at a temperature 7-9 °C higher than T(cm), and decreases at higher temperature due to the increased fluidity. The core viscosity is larger than that of the corona, and the corona viscosity increases toward the micelle center. The polymer concentration has different effects on the core and corona viscosity: the corona viscosity increases with a polymer concentration increase at the entire temperature range, whereas the core viscosity increases only at a low temperature. The corona viscosity increase is due to the condensation of a large number of polyethylene oxide (PEO) blocks. In contrast, the dehydration degree of polypropylene oxide (PPO) blocks in the core scarcely changes, and the core has a similar composition regardless of polymer concentration. The larger polymer concentration promotes a micelle formation at lower temperature where the fluidity increase is very weak, resulting in larger core viscosity.     

Unusual spectral shifts on fast violet-B and benzanilide: Effect of solvents, pH and β-cyclodextin

The absorption and fluorescence spectra of fast violet-B (FVB) and benzanilide (BA) have been analysed in different solvents, pH and β-cyclodextrin. The inclusion complex of FVB with β-CD is investigated by UV–visible, fluorimetry, AM 1, FTIR and SEM. The absorption maximum of FVB (anilino substitution) is red shifted than that of BA, but the benzoyl substitution hardly changed the ground state structure of BA. Compared to BA, the emission maxima of FVB largely blue shifted in cyclohexane and aprotic solvents, but red shifted in protic solvents and the longer wavelength maxima in FVB is due to the intramolecular charge transfer (TICT). In BA, the normal emission originates from a locally excited state and the longer wavelength band due to intramolecular proton transfer in non-polar/aprotic solvents and in protic solvents it is due to TICT state. β-CD studies reveal that, FVB forms 1:2 complex from 1:1 complex and BA forms 1:2 complex with β-CD.