一种新型长共轭结构咔唑衍生物的合成及其光学性质

以咔唑、N,N-二甲基甲酰氨、溴丁烷和对甲基苯乙烯为原料,经Wittig反应和Heck反应合成了一种新型的长共轭结构的咔唑衍生物——3-[(对甲基苯乙烯基)苯乙烯基]-N-丁基咔唑(4),其结构经1H NMR,IR和元素分析表征。用UV-Vis和荧光光谱初步探讨了4的光学性质,结果表明,4具有良好的光学性质。     

水溶性荧光高分子乙烯基咔唑—丙烯酸共聚物的合成及荧光测试

用偶氮二异丁腈作引发剂，使Ｎ－乙烯基咔唑和丙烯酸甲酯在苯中共聚合，该共聚物在四氢呋喃中用氢氧化钠水溶液水解，得到水溶性乙烯基咔唑－丙烯酸共聚物，该共聚物的水溶液在３７３ｎｍ处产生较强的荧光，其荧光强度随液ｐＨ值增大而增强，在该高分子水溶液中，加入不少量阳离子表面活性剂，其量子产率可提高７倍。微量重金属离子（Ｈｇ＾２＾＋）对荧光有一定的熄灭作用。荧光强度（ｌｏｇＩｏ／Ｉ）与Ｈｇ＾２＾＋的浓度呈线性关     

水溶性荧光高分子乙烯基咔唑－丙烯酸共聚物的合成及荧光测试

用偶氮二异丁腈作引发剂，使Ｎ－乙烯基咔唑和丙烯酸甲酯在苯中共聚合，该共聚物在四氢呋喃中用氢氧化钠水溶液水解，得到水溶性乙烯基咔唑－丙烯酸共聚物。该共聚物的水溶液在３７３ｎｍ处产生较强的荧光，其荧光强度随溶液ｐＨ值增大而增强，在该高分子水溶液中，加入少量阳离子表面活性剂，其量子产率可提高７倍，微量重金属离子（Ｈｇ（２＋））对荧光有一定的熄灭作用。荧光强度（ｌｏｇＩ０／Ｉ）与Ｈｇ（２＋）的浓度呈线性关系。     

亲水性咔唑共聚物和钼簇合物之间的作用及其溶液荧光

研究了Ｎ－乙烯基咔唑－丙烯酸共聚物（ＮＶＣ－ＡＡ）和微量的钼簇合物「Ｍｏ３Ｏ２（Ｏ２ＣＣＨ３）６（Ｈ２Ｏ）３」Ｂｒ２．２Ｈ２Ｏ在水溶液相互作用及其溶液荧光。实验发现,体系中存在单体荧光（３７５ｎｍ）和二聚体激态缔合物荧光（５００ｎｍ）。荧光强度分别随钼簇合物的浓度啬和ｐＨ值的提高而增强。     

新型偶氮化合物的合成及其光学性质

以咔唑和苯酚为原料,经重氮和偶合反应合成了一种新型偶氮化合物--N-对(4-羟基苯偶氮基)苯基-3,6-二(叔丁基)咔唑(4),其结构经1H NMR和13C NMR表征.4的 UV和固体荧光光谱研究结果表明,4具有较好的光学活性.     

1,4-二[(9-苯基)-9H-3-咔唑基)]苯的合成及其光电性能

以对二溴苯和(9-苯基)-9H-3-咔唑硼酸为原料,通过Suzuki偶联反应合成了一种新型含咔唑磷光主体材料——1,4-二[(9-苯基)-9H-3-咔唑基)]苯(1),其结构经1H NMR,13C NMR和IR表征。UV,荧光光谱和循环伏安法的光电性能研究结果表明,1具有咔唑基团的紫外-可见吸收和荧光特性,与4,4-二(9-咔唑)联苯相比,最低空轨道的能级降低。     

3-苯并噻唑-6-甲酰基咔唑的合成

本文以咔唑作为起始原料,经过烷基化、甲酰化、环化、甲酰化等步骤,合成了3-苯并噻唑-6-甲酰基咔唑,其结构经HNMR和MS表征,并初步研究了其荧光光谱。     

含二苯胺2,6-二咔唑基吡啶共轭化合物的合成

以咔唑,2,6-二溴吡啶和二苯胺为原料,经Ullmann和碘代反应合成了4个含二苯胺2,6-二咔唑基吡啶共轭化合物:3-二苯胺基-2,6二咔唑基吡啶,3,3’-二(二苯胺基)-2,6-二咔唑基吡啶,3,3’,6-三(二苯胺基)-2,6-二咔唑基吡啶和3,3’,6,6’-四(二苯胺基)-2,6-二咔唑基吡啶,其结构经1H NMR和IR确证。     

新型咔唑取代乙炔化合物的合成

分别以咔唑和2-羟基咔唑为原料,通过Sonagashira偶联反应和N-烷基化反应合成了6个新型的咔唑取代乙炔化合物:2-乙炔基-9-苄基咔唑,2-乙炔基-9-正丁基咔唑,2-乙炔基-9-正己基咔唑,3-乙炔基-9-苄基咔唑,3-乙炔基-9-正丁基咔唑和3-乙炔基-9-{4·[4·(硝基)苯基偶氮苯]氧}亚丁基咔唑,其...     

荧光素与咔唑分子内的光致电子转移反应

合成了以-(CH_2)_4-连接的荧光素,咔唑二元化合物,运用吸收光谱,荧光光谱及荧光寿命研究了咔唑在荧光素不同取代位置上的二元化合物分子内的光致电子转移过程,结果表明:分子内电子转移以动态过程为主.且当咔唑接在荧光素2’羧基端时,荧光素与咔唑的面对面取向较咔唑接在荧光素6位羟基端的肩并肩取向更有利于光致电子转移反应.     

同步荧光分析法的应用及其新进展*

同步荧光技术是解决多组分荧光物质同时测定的良好手段之一.本文从恒波长同步荧光法、恒能量同步荧光法、可变角同步荧光法、恒基体同步荧光法以及它们与导数技术、低温技术、化学计量学方法的联用等方面对同步荧光技术领域出现的新技术及应用作一评述.     

Water-soluble fluorescent boronic acid compounds for saccharide sensing: substituent effects on their fluorescence properties

Four new naphthalene-based boronic acid compounds (1-4) were synthesized. The effect of various carbohydrates on their fluorescence properties has been studied in aqueous phosphate buffer at pH 7.4. Different substitutions on the aniline group of the naphthalene ring resulted in significant differences in fluorescence properties for these four compounds. Compound 1 shows ratiometric fluorescence changes upon addition of a sugar. Compounds 2 and 3 do not show ratiometric fluorescence changes but show very large fluorescence intensity changes (about 70-fold fluorescence intensity increase). In addition to the quantifiable fluorescence property changes upon sugar addition, the fluorescence color changes of 1-3 are also visible to the naked eye. However, amidation of the aniline nitrogen atom significantly diminishes the fluorescence intensity of compound 4. The crystal structure of one boronic acid provided some insight into the structural features that are important for the fluorescence properties of these compounds.     

空间分辨荧光分析技术

空间分辨荧光分析技术突破了传统荧光分析的局限,为获得空间定位信息提供了技术保障。系统地综述了构成该技术的共焦荧光法、全内反射荧光法、多光子荧光法以及近场荧光法等4种方法的原理、特点、发展及其应用,并且强调了其在单分子测定中的作用。引用文献64篇。     

Meso-四对甲氧基苯基卟啉荧光被Hg（Ⅱ）猝灭后荧光恢复的研究

通过 meso-四对甲氧基卟啉荧光被Hg2 猝灭后荧光恢复这一现象证明了卟啉的自组装行为.meso-四对甲氧基苯基卟啉丙酮溶液荧光加入Hg2 后猝灭,少量水的引入使卟啉通过氢键发生自组装,这时荧光恢复.Hg2 加入后立即发生猝灭,但是恢复却是比较缓慢的,连续加入Hg2 ,荧光呈周期性的猝灭和恢复.并且通过荧光光谱和紫外光谱论证了这一现象.     

酪氨酸的分频荧光光谱研究

酪氨酸在300nm处产生一个荧光峰,在600nm处产生一个1／2分频荧光峰,在900nm处产生一个1／3分频荧光峰,此三峰具有相似的荧光特性。根据非线性光学分频荧光原理探讨了酪氨酸分频荧光峰产生的原因。     

Spectrum Correction in Study of Solvation Dynamics by Fluorescence Non-collinear Optical Parametric Ampli cation Spectroscopy

Femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectroscopy can extract the curve of spectral gain from its parametric superfluorescence. This unique spectrum correction method enables fluorescence non-collinear optical parametric amplification spectroscopy acquiring the genuine transient fluorescence spectrum of the studied system. In this work we employ fluorescence non-collinear optical parametric amplification spectroscopy technique to study the solvation dynamics of DCM dye in ethanol solution, and confirm that genuine solvation correlation function and shift of peak frequency can be derived from transient fluorescence spectra after the spectral gain correction. It demonstrates that fluorescence non-collinear optical parametric amplification spectroscopy can benefit the research fields, which focuses on both fluorescence intensity dynamics and fluorescence spectral shape evolution.     

三维同步荧光法研究喜树生物碱衍生物的荧光光谱性质

本文用三维同步荧光法详细研究了喜树生物碱衍生物的共性和特性,以及它们之间荧光光谱的变化过程,说明结构、取代基和溶剂在荧光光谱的变化中所起的作用,并用同步荧光法不经分离同时测定实际样品中的喜树碱和羟基喜树碱。     

Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy

Clinical studies have shown that in vivo fluorescence spectroscopy can improve the diagnosis of cervical precancer. Recent work suggests that epithelial fluorescence increases, whereas stromal fluorescence decreases, with precancer. However, the microanatomic and biochemical sources of fluorescence in living cervical tissue have not yet been established. This study aims to characterize the origins of living normal and precancerous cervical fluorescence at microscopic levels using laser-scanning fluorescence confocal microscopy. Ten pairs of colposcopically normal and abnormal biopsies were obtained; transverse, 200 microm thick, short-term tissue cultures were prepared and imaged when viable with UV (351-364 nm) and 488 nm excitation before and after addition of the vital dye, Mitotracker Orange. In normal epithelium basal epithelial cells showed cytoplasmic fluorescence; parabasal, intermediate and superficial cells showed fluorescence only at the periphery of the cell. In low-grade precancers cytoplasmic fluorescence was visible in the bottom one-third of the epithelium; in high-grade precancers cytoplasmic fluorescence was visible throughout the lower two-thirds of the epithelium. Cytoplasmic fluorescence was colocalized with the MitoTracker probe and is attributed to mitochondrial reduced form of nicotinamide adenine dinucleotide at UV excitation and mitochondrial flavin adenine dinucleotide at 488 nm excitation. Stromal fluorescence originated from matrix fibers; with the development of precancer the density and fluorescence intensity of matrix fibers decrease. Autofluorescence properties of precancerous cervix reflect an increased number of metabolically active mitochondria in epithelial cells and a reduced stromal fluorescence, which can be an indicator for altered communication between precancerous epithelium and stroma. These changes can explain differences in in vivo fluorescence spectra of normal and precancerous cervical tissue.     

External electric field effects on fluorescence of pyrene butyric acid in a polymer film: concentration dependence and temperature dependence

Fluorescence spectra and electrofluorescence spectra (plots of the electric field-induced change in fluorescence intensity as a function of wavelength) have been measured at different temperatures for pyrene butyric acid (PBA) in a PMMA film at different concentrations. At a low concentration of 0.5 mol % where fluorescence emitted from the locally excited state of PBA (LE fluorescence) is dominant, LE fluorescence spectra show only the Stark shift in the presence of an electric field (F), which results from the difference in molecular polarizability between the ground and emitting states. At a high concentration of 10 mol % where the so-called sandwich-type excimer fluorescence (EX(1)) is dominant, both EX(1) and LE fluorescence are quenched by F. Another fluorescence assigned to a partially overlapped excimer (EX(2)) also exists at room temperature, and this emission is enhanced by F. As the temperature decreases, three fluorescence emissions whose electric field effects are different from each other become clear besides EX(1) and LE fluorescence, indicating that at least five fluorescence components exist at high concentrations at low temperatures. At a medium concentration of 5 mol % where EX(1) is comparable in intensity to the LE fluorescence, the intensity of EX(1) is not affected by F at any temperature, but LE fluorescence and EX(2) are markedly influenced by F at room temperature, and four fluorescence emissions are confirmed at low temperatures.     

Study on the Interaction of Pentachlorophenol with Urease in Aqueous Solution by Multiple Spectroscopic Techniques

The interactions between pentachlorophenol (PCP) and jack bean urease were studied using UV/vis absorption, CD, fluorescence, synchronous fluorescence, and three-dimensional fluorescence spectroscopic techniques. The fluorescence data showed that the fluorescence quenching of urease by PCP the results of the formation of a PCP–urease complex involving a hydrophobic interaction. The distance r between the donor (urease) and acceptor (PCP) was obtained from the fluorescence resonance energy transfer. The effect of PCP on the conformation of urease was analyzed using UV/vis absorption, synchronous fluorescence and three-dimensional fluorescence spectroscopic techniques. The result showed that PCP can enter into the hydrophobic pocket at the interface of urease and that the micro environments around the tyrosine and tryptophan residues were changed.