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A series of 1-naphthanilides (1) and 2-naphthanilides (2) with varied substituents at the para- or meta-position of anilino phenyl ring were prepared and their absorption and fluorescence spectra in a nonpolar solvent cyclohexane were investigated. An abnormal long wavelength emission assigned to the charge transfer (CT) state was found for all of the prepared naphthanilides in cyclohexane. A linear free energy correlation between the CT emission energies and the Hammett constants of the substituent was found within series 1 and 2. The value of the linear slope with 1 (0.42 eV) was higher than that with 2 (0.32 eV) being close to that of the substituted benzanilides 3 (0.31 eV) The higher slope value suggested higher charge separation extent in the CT state of 1 than that of 2. It was found that the corresponding linear slope of anilino-substituted benzanilides remained unchanged when para-, meta-, ortho-, or ortho, ortho-methyls were introduced into the anilino moiety, which ruled out the possible contribution of the difference in the steric effect and the electron accepting ability of the naphthoyl acceptor in 1 and 2. Compared with the early reported N-substituted-benzoyl-aminonaphthalene derivatives 4 and 5, it was considered that 1-naphthoyl enhanced the charge transfer in 1 and the proximity of its ^1La and ^1Lb states was suggested to be responsible. It was shown that 1- and/or 2-substituted naphthalene cores acting as either electron acceptor (naphthoyl) or electron donor (aminonaphthalene) were different in not only electron accepting (donating) ability but also shaping the charge transfer pathway.  相似文献   
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胆酸盐是一类生物表面活性剂, 一般含有羟基取代的类固醇骨架, 并有一带负电的尾链, 较为常见的胆酸盐有胆酸钠、 脱氧胆酸钠、 牛磺胆酸钠及牛磺脱氧胆酸钠等. 其分子结构见表1及图1所示.  相似文献   
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建立了以滤纸为基质的中草药有效成分补骨脂素、异补骨脂素的固体表面室温燐光 分析法。对影响室温燐光强度的各种因素进行了详细的研究,实验表明,补骨脂素的线性范围 为2×10-6~2×10-4mol/L;检出限为0.47ng/斑,异补骨脂素的线性范围为4×10-6~4×10-4mol/L;检出限为0.17ng/斑。  相似文献   
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胆酸盐是一类生物表面活性剂 ,一般含有羟基取代的类固醇骨架 ,并有一带负电的尾链 ,较为常见的胆酸盐有胆酸钠、脱氧胆酸钠、牛磺胆酸钠及牛磺脱氧胆酸钠等 .其分子结构见表 1及图 1所示 .Fig.1 Molecular structure of cholate surfactant胆酸盐是两亲分子 ,具有疏水性凸面和亲水性的凹面 ,在溶液中胆酸盐单体背靠背通过疏水 -亲脂作用力形成一个疏水内芯 ,亲水面朝向溶剂的簇集体 ,并增溶疏水性的小分子于簇集体内芯 ,使之处于一个疏水而高度保护的微环境中 .另外 ,胆酸盐单体之间通过疏水 -亲脂相互作用 ,可形成螺旋形簇集体 .由于具…  相似文献   
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以环糊精及其衍生物为手性选择剂,通过优化缓冲液的浓度、酸度以及采用环糊精的种类和浓度等,建立了罗格列酮钠对映体的水介质和非水介质两种毛细管电泳拆分方法.最佳条件为:150 mmol/LTris-H3PO4缓冲液,pH=2.0,含有1 mmol/Lβ-CD或DM-β-CD,10%(ψ)甲醇的运行液,分离电压为25 kV,检测波长215 nm.也可以使用含有9 mmol/L HDMS-β-CD,20 mmol/L磷酸和10 mmol/L NaOH的甲醇电泳液.两种拆分体系均实现了罗格列酮钠对映体的基线分离,而且拆分效率基本相当.方法简便、快速,可作为罗格列酮钠的手性分离方法.  相似文献   
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刘力宏  张晗  张煊  江云宝 《中国化学》2005,23(4):421-426
Two dual fluorescent receptors (1 and 2) for monosaccharides based on 4-dialky(alkyl=methyl and n-butyl) containing boronic acid group at the amido aniline were synthesized and their spectral properties were investigated. These receptors exhibited dual fluorescence with the long-wavelength band displaying strong solvent-polarity dependence, indicating the occurrence of the excited-state intramolecular charge transfer (ICT).With increasing pH value in aqueous solutions, the hybridization of the boron atom changed from sp^2 to sp^3, inducing a decrease in the total fluorescence quantum yield. The experimental results indicated that the anionic form of the boronate group acted as an electron donor and the benzanilide-like charge transfer was promoted upon hybridization change. In the presence of monosaccharides, the boronic acid in 1 and 2 changed from neutral to anionic form. The intensity of the locally excited (LE) state emission decreased in the presence of sugars while a slight increase in the intensity at the charge transfer (CT) emission occurred. Based on the change in the CT to LE intensity ratios of 1 and 2 due to sugar binding, ratiometric fluorescent assays for monosaccharide sensing were established.  相似文献   
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评述了苯甲酰苯胺及其衍生物的发光行为和电荷转移/质子转移光物理模型的研究进展,并展望了该类新型分子内电荷转移荧光体在化学及生物分子识别与传感中的潜在应用前景.  相似文献   
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