Enhanced Enantioselective Recognition with Diastereoisomeric BINOL Based Chiral Fluorescent Boronic Acid Sensors

We prepared the diastereoisomers of BINOL based bisboronic acid chiral probes (the probes are with dual chirogenic centers) for enantioselective recognition of chiral analytes, such as tartaric acids, D-sorbitol, etc. We found the diastereoisomeric probes give different emission intensity-pH profiles, a phenomenon was reported, probably, for the first time. We found that with the second chirogenic center, the selectivity of the probes toward chiral analytes can be improved. For example, the diastereoisomeric probes give drastically different response to D-sorbitol, the same selectivity was not found for the BINOL bisboronic acid probes with single chirogenic center. Our result with the diastereoisomeric probes is helpful for design of new chiral molecular probes to enhance the selectivity of the boronic acid sensors toward chiral analytes.     

Synthesis and Chiral Recognition Properties of Novel Fluorescent Chemosensors for Amino Acid

The charge neutral chiral optical sensors 1a∼d containing thiourea and amide groups were synthesized by simple steps in good yields and their structures were characterized by IR, ¹H NMR, ¹³C NMR, MS spectra and elemental analysis. The enantioselective recognition for α-phenylglycine and phenylglycinol was examined by fluorescence emission and UV-vis spectra. The fluorescence and UV-vis spectra changes of 1a were obvious when the enantiomers of α-phenylglycine anion were added, which exhibited that 1a has good enantioselective recognition ability towards α-phenylglycine. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Boronic Acid Based Modular Fluorescent Sensors for Glucose

Modular photoinduced electron transfer (PET) sensors bearing two phenylboronic acid groups, one or two fluorophores: pyrene(a), phenanthrene(b), anthracene(c), 1-naphthalene(d), 2-naphthalene(e) and alkylene linkers, from trimethylene(3) to octamethylene(8), have been evaluated. Systems with a single pyrene fluorophore 34a, 35a and 36a bind the strongest with D-glucose (36a also binds well with D-melibiose). Whilst 37a and 38a bind the strongest with D-galactose. Changing the fluorophore, also, influences the binding, 36a, 36b and 36c are D-glucose selective, whilst 36d and 36e are D-galactose selective. Systems with two fluorophores 36a-a and 36a-b show an overall decrease in binding efficiency. Energy transfer in 36a-b results in enhanced sensitivity and selectivity towards D-glucose.     

萘酰亚胺衍生物的合成及对苦味酸的检测

设计并合成了萘酰亚胺衍生物N-正己基-4-[2-(3-苯基硫脲)-乙氨基]-1,8-萘酰亚胺(HTN),通过NMR和MS表征了其结构。利用荧光光谱法研究了HTN对苦味酸(PA)的识别作用。研究发现,在C₂H₅OH/H₂O (2:1)体系中,HTN荧光强度随PA浓度的增加而大幅度下降。PA浓度在1×10^-6~5×10^-4 mol·L^-1范围内时,猝灭率(I₀-I)/I₀与[PA]^0.5呈线性关系,R²=0.995 5。常见苯系物,如苯胺、苯甲醛、三硝基甲苯、苯酚、苯乙烯、吡啶、对甲苯磺酸、甲苯、硝基苯及氯苯等均不干扰HTN对PA的识别。结果表明,HTN对PA具有较好的选择性和灵敏度。     

Synthesis, Physical Properties and Cytotoxicity of Stilbene-Triazine Derivatives Containing Amino Acid Groups as Fluorescent Whitening Agents

A series of novel stilbene-triazine derivatives containing amino acid groups were synthesized and screened to evaluate their cytotoxicity. The UV absorptions of the derivatives were in the range of 240–450 nm. The absorption peaks of the cis-isomers and trans-isomers were in 281–291 nm and 353–361 nm, respectively. Their fluorescence emission peaks of the derivatives were located in the range of 400–650 nm. The whiteness data indicated that all the stilbene-triazine-amino acid derivatives showed excellent whitening effect on cotton fiber compared to untreated cotton. The preliminary cytotoxicity of these derivatives on a mouse fibroblast cell line (L-929 cells) was also investigated. The results showed that the compounds (7a–h) were nontoxic to L-929 cells as fluorescent whitening agents.     

Spectroscopic and Photophysical Characterization of Fluorescent Chemosensors for Monosaccharides Based on N-Phenylboronic Acid Derivatives of 1,8-Naphthalimide

Spectroscopic and photophysical properties of two fluorescent probes for monosaccharides are presented. Probes are based on the N-phenyl-1,8-naphthalimide structure having the boronic acid group [R-B(OH)₂] in ortho in one case, and meta in the other case, positions of the N-phenyl group. Formation of the anionic form of the boronic acid group [R-B(OH)^– ₃] induced a substantial decrease of the steady-state fluorescence of both compounds. Because no change in the fluorescence lifetime from the neutral to the anionic forms is observed, static quenching resulting from photoinduced electron transfer from the anionic form of the boronic acid is used to explain the decrease of the emission intensity. Both compounds show substantial decreases of their fluorescence intensity in the presence of sugars. In addition, this decrease of the fluorescence intensity is associated with an increase of the fluorescence lifetime for the ortho derivative while no effect on the lifetime is observed for the meta derivative. Both photoinduced electron transfer and steric hindrance are discussed to correlate the observed results.     

Bodipy Based Fluorescent Materials in Cellulose Matrices: Synthesis,Spectral Properties and Vapochromic Fluorescent Recognition of Alcohols and Acetone

This paper highlights advances made using the 4-bora-3a,4a-diaza-s-indacene (BODIPY) as a fluorophore in design and application of fluorescent sensors for microenvironment polarity. Sections of the paper cover broad analysis of a range of fluorescent indicators immobilized in ethyl- and methyl cellulose matrices. The present study demonstrates that BODIPY-based fluorescent materials could be successfully utilized for ratiometric detection of ethanol and acetone in gas phase. The achieved limit of detection value equals 0.02 mg/ml for acetone and 0.08 mg/ml for ethanol, whereas obtained sensoric materials are reusable without regeneration required.

     

含氨基酸席夫碱的5-氟尿嘧啶类衍生物的合成及Raman光谱分析

以N1-(2-四氢呋喃烷基)-5-氟尿嘧啶为原料,合成了三种含氨基酸席夫碱的5-氟尿嘧啶类衍生物,用元素分析,1HNMR表征了它们的结构。用拉曼光谱(RS)和表面增强拉曼光谱(SERS)分析了目标化合物的分子振动形式,比较它们在RS和SERS中的异同点。     

A Colorimetric and Fluorescent Sensor for Iron Recognition Based on Rhodamine Derivative

A novel rhodamine based fluorescent sensor, L, was developed and investigated as a colorimetric and fluorescent sensor for Fe³⁺ in dimethyl sulfoxide. The compound L showed a good selectivity and sensitivity toward Fe³⁺ in the presence of large excess of other competitive ions. L can be used as a colorimetric and fluorescent sensor for Iron recognition in potential.     

氨基酸衍生三维荧光法结合多维模式识别用于蜂蜜种类辨别研究

确认食品的种类和产地等信息是食品质量与安全研究的重要内容。基于蜂蜜中的氨基酸种类和含量的不同,应用甲醛和乙酰丙酮与蜂蜜中氨基酸发生荧光衍生反应对源自不同花源的蜂蜜进行种类辨别研究。实验首先研究了衍生剂用量、时间、温度及pH值对蜂蜜中氨基酸荧光衍生反应的影响。然后在激发光波长范围为300～500 nm和发射光波长范围380～580 nm下对衍生后的蜂蜜进行三维荧光检测,每个蜂蜜样品经检测后得到一个三维荧光光谱矩阵数据,五种蜂蜜共150个样品最后得到一个三维立方数据。将检测获得的三维荧光数据结合多维主成分分析(M-PCA)、自加权交替三线性分解法(SWATLD)及多维偏最小二乘辨别分析(N-PLS-DA)等多维模式识别方法,进行数据处理并获取五种蜂蜜的识别信息。三种多维模式识别方法分别都展示出不同种类蜂蜜的聚类趋势,相比较而言,由于N-PLS-DA充分利用了衍生蜂蜜荧光的所有信息,所以取得了更加准确和可靠的分类结果,对五种蜂蜜的总识别率为88%。研究结果显示基于氨基酸荧光衍生的多维模式识别方法可以用于蜂蜜种类的识别研究。该研究为无荧光或弱荧光自然物质的直接荧光辨别分析提供了一种新思路。     

Fluorescent Triphenyl Substituted Maleimide Derivatives: Synthesis,Spectroscopy and Quantum Chemical Calculations

In this paper we describe a semi-empirical quantum method for predicting the wavelength of maximum fluorescence excitation and emission for several known and new maleimide derivatives. All new maleimides, containing a N-Benzyl attachment, were successfully synthesised via a tandem Suzuki reaction with aryl boronic acids containing either an electron donating, electron withdrawing functional groups. Absorption and emission spectra calculated using the semi-empirical AM1 method with excited state ZINDO calculations proved more reliable than either Hartree-Fock Configuration interaction or time dependent density functional methods. Calculated absorption and emission wavelengths were compared with 26 experimental spectra from known or newly synthesised maleimides and found to have provide reasonable predictions, with an average deviation of less the 6% for absorption maxima and less than 4% for emission peaks. The described method provides a strong benchmark for the accuracy that can be expected from theoretical predictions of fluorescence spectra.     

Synthesis, Fluorescence Properties and Theoretical Calculations of Novel Stilbene Derivatives Based on 1,3,4-Oxadiazole Bearing Anthracene Core

Two novel stilbene derivatives bearing anthracene core based on 1,3,4-oxadiazole were efficiently synthesized and characterized by ¹H-NMR, mass spectrometry and elemental analysis. The optical properties of the title compounds were investigated by UV–vis absorption and fluorescence emission spectra in different solvents. Chemical calculations were performed by density functional theory (DFT) at the (B3LYP)/6-31G* level. The results show the two compounds exhibit strong green fluorescence emission ranged from 489–493 nm, and the fluorescence quantum yield ranged from 0.78–0.92. Their HOMO and LUMO levels are (?5.44 eV, ?2.25 eV) and (?5.45 eV, ?2.28 eV), respectively. The influence of the solvent on the fluorescence intensities was also discussed.     

New spiro[benzotetraphene-fluorene] Derivatives: Synthesis and Application in Sky-Blue Fluorescent Host Materials

Blue light-emitting spiro[benzotetraphene-fluorene] (SBTF)-based host materials, 3-(1-naphthyl)-10-naphthylspiro[benzo[ij]tetraphene-7,9′-fluorene] (1), 3-(2-naphthyl)-10-naphthylspiro[benzo[ij]tetraphene-7,9′-fluorene] (2), and 3-[2-(6-phenyl)naphthyl]-10-naphthylspiro[benzo[ij]tetraphene-7,9′-fluorene] (3) were designed and prepared via multi-step Suzuki coupling reactions. Introducing various aromatic groups into SBTF core lead to a reduction in band gap and a determination of the color purity and luminescence efficiency. Typical sky-blue fluorescent organic light emitting diodes with the configuration of ITO/N,N′-di(1-naphthyl)-N,N′-bis[(4-diphenylamino)phenyl]-biphenyl-4,4′-diamie (60 nm)/N,N,N′,N′-tetra(1-biphenyl)-biphenyl-4,4′-diamine (30 nm)/host: dopant (30 nm, 5 %)/LG201 (electron transporting layer, 20 nm)/LiF/Al were developed using SBTF derivatives as a host material and p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-Ph) as a sky-blue dopant material. A device obtained from three materials doped with DSA-Ph showed color purity of 0.148 and 0.239, a luminance efficiency of 7.91 cd/A, and an external quantum efficiency >4.75 % at 5 V.     

基于亚甲基蓝的近红外荧光探针用于HOCl的特异性检测

次氯酸(HOCl)是一种由过氧化氢和氯离子在髓过氧化物酶(MPO)催化作用下产生的活性氧。由于其在机体抵抗病原体的免疫防御中起着至关重要的作用,因此对HOCl的识别和检测具有非常重要的意义。目前,检测HOCl的方法有电分析法、色谱法、化学发光法和荧光分析法,其中荧光检测法以其简单、快速、高选择性、高灵敏度和实时检测等突出优点引起了许多研究者的兴趣。本文以亚甲基蓝(Methylene blue,MB)为荧光母核,设计合成了一种近红外荧光探针MB-1用于HOCl的特异性检测。该探针可在体外特异性检测HOCl,响应之后,荧光会有显著的增强,同时伴有溶液颜色从无色到蓝色的明显变化。该探针对HOCl具有较高的灵敏度,其检测限为8.2 nmol/L。此外,该探针具有较好的抗干扰能力,为在生理水平上检测HOCl提供了可能。     

基于功能性核酸识别的荧光各向异性分析方法与应用

荧光各向异性方法又称荧光偏振法,基于相互作用的分子结合前后发射光退偏振的不同而实现对相互作用的研究或对目标物的检测。20世纪50年代Gregorio Weber用荧光各向异性法研究了氮磺酰氯与牛血清白蛋白和卵清白蛋白的作用,开启了该方法在生物化学研究中应用的先河。而20世纪90年代开始的功能性核酸(FNAs,包括核酸适配体和核酸酶等)的发现与合成,使基于功能性核酸的传感得到了广泛的应用。核酸适配体能够特异性识别目标分子,基于核酸识别的荧光各向异性分析方法具有高选择性、高灵敏度、高通量等优势,在研究蛋白质、核酸和小分子的相互作用中起到重要作用,然而如何提高结合前后的荧光各向异性信号变化,尤其是小分子识别前后,在基于功能性核酸识别的分析方法发展中是一个挑战。介绍了基于功能性核酸识别的荧光各向异性的方法应用于检测蛋白质、核酸及其他在生命活动中起重要作用的小分子的基本原理及设计理念。     

基于四苯乙烯基的水杨醛缩芳胺希夫碱化合物的合成及性能研究

将四苯乙烯基与取代水杨醛通过碳氮双键连接起来,合成了基于四苯乙烯基的水杨醛缩芳胺希夫碱TPE-SA1、TPE-SA2、TPE-SA3、TPE-SA4、TPE-SA5。利用IR、NMR、MS和元素分析等对其分子结构进行表征,通过紫外-可见光谱、分子荧光光谱、循环伏安分析法和热重测试分别考察了该类化合物的光学、电化学和热稳定性质。实验结果表明:该类化合物在纯THF溶液中,分别在260 nm和370 nm左右处出现B带和R带紫外吸收峰;在四氢呋喃/水的混合溶液中,表现出典型的聚集诱导发光(AIE)性能。目标化合物的热分解温度分别为262,283,295,278,299℃,具有较好的热稳定性。它们的电离势分别为5.31,5.43,5.41,5.30,5.15eV,电子亲合势均大于4.3 eV。     

基于苯并三氮唑类化合物的铱络合物的合成及性能

金属铱络合物由于其特殊的光物理化学性质而得到了广泛的关注。主要研究了配体为苯并三氮唑衍生物的三种新型铱配合物,Ir(TBT)、Ir(EBT)和Ir(CBT)的合成及表征,并对其物理性能进行了一定的研究。通过研究发现该类铱化合物的最大发射波长可以通过修饰配体调节,其中化合物Ir(TBT)的最大发光峰为598nm,并且利用Gaussian 03、B3LYP/6-31G*程序对三个配体进行量子化学计算,计算结果与实验结果吻合。通过差热分析法对其进行热稳定性测试后发现其玻璃化温度为133℃,该类化合物在电致发光领域具有潜在的应用价值。     

氨基膦酸螯合纤维合成和吸附性能的红外光谱研究

在氨基膦酸螯合纤维的制备过程中,用红外光谱法对聚丙烯接枝苯乙烯、乙酰基和多胺系列和氨基膦酸螯合纤维进行了定性研究,用半定量的红外光谱法对氨基膦酸纤维的功能化程度进行了考察,还对氨基膦酸螯合纤维吸附铟和铜后的红外光谱进行了研究。研究表明：(1)钠型氨基膦酸螯合纤维在1 116 cm-1出现了—P(ONa)₂的新峰,验证了基的有效膦酸化。(2)制备过程中,通过红外光谱中1 056和1 110 cm-1峰的变化可以反映出膦酸化的程度。(3)氨基膦酸螯合纤维吸In3+后形成新的N—In配位键,在1 107 cm-1处出现强而宽大的吸收峰,同时在699和617 cm-1出现两个强吸收峰; 氨基膦酸螯合纤维吸附Cu2+形成配合物后,在1 110和618 cm-1处出现两个强而宽的新峰。(4)通过对光谱中1 200～900 cm-1和600 cm-1之间的峰的变化和峰面积的比较,可以反映出氨基膦酸螯合纤维对铟和铜的吸附性能。     

聚乙烯醇与氨基酸接枝共聚物的合成及光谱研究

本文致力于氨基酸类高分子药物的合成、表征。研究目的是研制一种氨基酸类高分子药物用于临床治疗；研究方法是将氨基酸与选定的高分子化合物进行高分子化学反应，联结到高分子链上；研究结果是合成了聚乙烯醇与氨基酸（甘氨酸、丙氨酸）的共聚物，用红外光谱、核磁共振谱对共聚物进行了分析和表征，并通过谱图对氨基酸的转化率进行了讨论，结果证明产物符号要求，且甘氨酸比丙氨酸的转化率高。