一种基于苯并噻二唑衍生物的F~-荧光探针分子的理论研究

用密度泛函理论研究了最近实验上合成的一种基于苯并噻二唑衍生物的F~-荧光探针(1)的性质.通过对相关化学反应热力学参数的计算,提出了1对F~-具有高选择性的可能原因;同时用含时密度泛函理论对电子吸收光谱和荧光发射光谱进行了理论计算,解释了实验光谱.     

基于有机硅化合物的反应型氟离子荧光化学传感器

作为半径最小的阴离子,氟离子(F-)表现出高电负性和强碱性,因而具有特殊的化学性质。由于F-与人类健康和环境安全密切相关,因此它的识别与检测已引起了人们极大的关注。到目前为止,用于选择性检测F-的荧光化学传感器已有大量报道,这些传感器主要是基于有机硼化合物和氢键质子给体。与这些传感器相比,反应型传感器具有更高的选择性,并且更容易在水环境中实现F-检测。本文根据有机硅化合物的结构不同,分别综述了近年来基于硅醚、硅炔及其他有机硅化合物的反应型氟离子荧光化学传感器的合成研究进展,其中包括本课题组的一些研究工作。     

新型苯并噻二唑-7-羧酸衍生物的合成

以2,3-二氯硝基苯和异丙硫醇为原料,设计并合成了3个新型的苯并噻二唑-7-羧酸衍生物,其结构经1H NMR,IR和元素分析表征.     

一种基于苯并噁唑类的可视化检测汞离子的荧光探针

设计合成了一种用于检测Hg²⁺的苯并噁唑类荧光探针4-(苯并[d]噁唑-2-基)-2-((二(2-(乙巯基)乙基)氨基)甲基)苯酚(ZY1), 用质谱、核磁氢谱和X射线单晶衍射等方法对其进行了结构表征, 并考察了其光谱性能. 研究结果表明, ZY1对Hg²⁺有较高的选择性和灵敏度, 它们之间的结合比为1:1, 共存离子及pH值(3.0～9.0)对其测定影响小. ZY1能够可视化检测Hg²⁺, 并在HeLa活细胞中实现了汞离子的成像, 这对检测生物体内的Hg²⁺将具有潜在的应用价值.     

共轭聚合物离子荧光化学传感器

荧光传感器能够将分子识别的信息转换成荧光信号,荧光法在灵敏度、选择性和实时原位检测等方面优势突出,最近已引起了人们很大的兴趣。本文主要介绍以共轭聚合物为基础的离子荧光化学传感器的近期研究进展,重点综述了共轭聚合物的荧光化学传感器在阳离子识别检测中的分子设计、合成、作用机理和应用,并展望了该领域的发展方向。     

苯并噻二唑类有机太阳能电池材料研究进展

苯并噻二唑结构单元被广泛用来构建高光电转换效率的有机太阳能电池材料.从聚合物太阳能电池、有机小分子太阳能电池以及染料敏化太阳能电池三个方面系统地综述了近年来含苯并噻二唑基团的有机太阳能电池材料的研究进展,并对其发展趋势和应用前景做了展望.     

亚硫酸根离子荧光化学传感器的研制

亚硫酸根离子对固定于聚氯乙烯(PVC)膜中的5,10,15,20四苯基卟啉(TPP)/t(2,6二氧异丁基)β环糊精(DOBβCD)有可逆荧光熄灭作用。据此研制成测定亚硫酸根离子浓度的荧光化学传感器,该传感器敏感膜最佳组成质量分数为PVC308%,BOS615%,TPP150%,DOBβCD620%。在pH=65的KOHKH2PO4缓冲溶液底液中测定亚硫酸根离子,其线性响应范围为622×10-6～311×10-4mol/L,检测限为780×10-7mol/L,其响应时间小于40s。其它常见阴离子和阳离子不干扰测定。可用于实际样品中亚硫酸根离子含量的测定。     

水相氟离子“turn-on”型荧光传感器

设计合成了香豆素衍生物7-(二叔丁基(对硝基苯醚)硅醚)-4-甲基-香豆素(DTBPC),研究了DTBPC在水中对氟离子的响应.在表面活性剂十六烷基溴化铵的存在下,氟离子断裂DTBPC分子中的Si—O键释放出香豆素阴离子,从而"turn-on"体系的荧光,响应时间为3min,检测限为60ppb,表明DTBPC可以在水相中高灵敏、快速、专一性地识别氟离子,有望应用于氟离子荧光传感器.     

含二呋喃基苯并噻二唑的聚芳炔类衍生物的合成与性能

以四(三苯基磷)钯(Pd(PPh3)4)和CuI为催化剂,在二异丙胺和四氢呋喃溶液中,采用宽能带的1,4-二乙炔基-2,5-二(十二烷氧基)苯(PE)和窄能带的4,7-双(5′-溴-2′-呋喃)-2,1,3-苯并噻二唑(FBT)合成了一系列新型聚芳炔。长链烷氧基的存在使得此类聚合物在常用的有机溶剂中具有较好的溶解性和成膜性。通过对上述聚合物的紫外-可见吸收、荧光发射及循环伏安等基本性能进行探讨可知,随着共聚物中FBT含量的增加,共聚物薄膜的吸收起始波长及荧光发射波长均有明显的红移。聚合物薄膜的最大发射峰位于600～650 nm,聚合物中的能量能有效地由PE单元转移到FBT单元上。     

新型苯并噻二唑衍生物的非线性光学性质理论研究

以苯并噻二唑分子为母体,设计了5个系列的衍生物,采用AM1半经验量子化学方法,研究了共轭π桥的不同增长方式和不同推拉电子基团对分子的电子结构及非线性光学性质的影响.结果表明:共轭链较短时,分子的二阶极化率和三阶极化率与共轭链长的线性相关性较好;而当共轭链较长时,分子的二价极化率和三阶极化率随着共轭链的增长而呈起伏性变化;与三氰基呋喃相比,三硝基呋喃对非线性极化率的影响更大;部分目标分子的一阶极化率α与Δμ·ΔE-1、二阶极化率β与α·ΔE-1、三阶极化率γ与α·ΔE-2和β·ΔE-1都有较好的相关性.     

Boron-dipyrromethene based specific chemodosimeter for fluoride ion

3,5-Bis(trimethylsilylethynyl)-4,4-difluoro-8-(4-tolyl)-4-bora-3a,4a-diaza-s-indacene [BODIPY(CCTMS)₂] has been synthesized by coupling of 3,5-dibromo-4,4-difluoro-8-(4-tolyl)-4-bora-3a,4a-diaza-s-indacene with trimethylsilylacetylene under pd(0) coupling conditions. The BODIPY(CCTMS)₂ was used as a selective colourimetric and fluorescent chemodosimeter for fluoride ion, following the F⁻ ion induced cleavage of trimethylsilyl group, the protecting group of ethyne functionality by monitoring the changes in UV-vis and fluorescence properties. The dosimeter BODIPY(CCTMS)₂ display clear changes in colour, absorption and emission bands selectively for F⁻ ion over other anions such as Cl⁻, Br⁻, I⁻, ClO₄⁻ and HPO₄²⁻.     

Tracking of mercury ions in living cells with a fluorescent chemodosimeter under single- or two-photon excitation

Tracking of Hg²⁺ in solutions as well as in living cells was conducted with a fluorescent chemodosimeter by measuring the spectral shift of its fluorescence under single- or two-photon excitation. The spectral hypsochromic shifts of this chemodosimeter when reacting with Hg²⁺ were found to be about 50 nm in acetonitrile/water solutions and 32 nm in Euglena gracilis 277 living cells. This chemodosimeter shows high sensitivity and selectivity, and is not influenced by the pH values. It can signal Hg²⁺ in solutions down to the ppb range under either single-photon excitation (SPE) at 405 nm or two-photon excitation (TPE) at 800 nm. However, with low cellular chemodosimeter concentrations, the SPE spectra were disturbed by the auto-fluorescence from the native fluorophore in the cell, while the TPE spectra were still of high quality since the two-photon absorption cross section of this chemodosimeter is much larger than that of the native fluorophores in the cell.     

A specific chemodosimeter for fluoride ion based on a pyrene derivative with trimethylsilylethynyl groups

Pyrene derivative 1 containing four trimethylsilylethynyl substituents was synthesized and investigated as a chromogenic and fluorescent chemodosimeter sensor for fluoride ions. 1 showed a high sensitivity and specific selectivity over a rapid response time toward fluoride anions compared to other anions, such as Cl(-), Br(-), ClO(4)(-), H(2)PO(4)(-) and HPO(4)(2-). TD-DFT calculations showed that the delocalization of the σ-electrons of the silicon destabilized the HOMO energy level of 1, thus red shifting both its absorption and emission spectrum. The addition of F(-) removed the trimethylsilyl substituents and resulted in a blue shift of both the absorption and fluorescent spectra of 1, which could be monitored by the color change with the naked-eye. Moreover, an easy to prepare test paper, which was obtained by immersing a filter paper into a THF solution of 1, could be utilized to detect and estimate the concentration of fluoride anions in water.     

Development of ratiometric fluorescent probe for zinc ion based on indole fluorophore

A water-soluble ratiometric fluorescent probe ZID-1 has been developed on the basis of an internal charge transfer (ICT) mechanism. Upon complexation with Zn²⁺ under physiological conditions, ZID-1 exhibits a significant blue shift of 77 nm in the emission spectrum. The fluorescent behavior of ZID-1 suggests that the pyridyl group incorporated into the fluorophore coordinates the metal ion as the fourth ligand and affords an appropriate binding affinity (K_d = 17.1 nM) for the intracellular imaging of Zn²⁺.     

Epoxy-based oligomeric probe bearing naphthalene units for selective turn-OFF fluorescent sensing of fluoride anion

A simple epoxy-based oligomer 1 bearing naphthalene unit at the chain-ends is reported to be highly selective ON–OFF type fluorescent probe for fluoride anion. The titled oligomer displayed fluorescence quenching upon addition of F^?, resulting in selective detection of fluoride anion over other anions, such as AcO^?, Cl^?, Br^?, I^?, HSO₄^?, NO₃^? and H₂PO₄^? in CH₃CN. Fluorescence experiments suggest the significant influence of the oligomer chain on the sensitivity and selectivity of 1 towards fluoride anion.     

Chromogenic and fluorescent ‘‘turn-on' chemodosimeter for fluoride based on F~–-sensitive self-immolative linker

A new chromogenic and fluorescent ‘‘turn-on" chemodosimeter 3 was designed and synthesized by using a fluoride-sensitive self-immolative linker, in combination with the fluorescent dyes 7-hydroxy-4-trifluoromethyl coumarin. The chemodosimeter exhibited high selectivity and sensitivity toward fluoride anions through ‘‘turn-on" chromogenic and fluorogenic dual modes.     

A ratiometric fluorescent probe for fluoride ion employing the excited-state intramolecular proton transfer

A ratiometric fluorescent probe 1 for fluoride ion was developed based on modulation of the excited-state intramolecular proton transfer (ESIPT) process of 2-(2′-hydroxyphenyl)benzimidazole (HPBI) through the hydroxyl group protection/deprotection reaction. The probe 1 was readily prepared by the reaction of HPBI with tert-butyldimethylsilyl chloride (TBS-Cl) and shows only fluorescence emission maximum at 360 nm. Upon treatment with fluoride in aqueous DMF solution, the TBS protective group of probe 1 was removed readily and ESIPT of the probe was switched on, which resulted in a decrease of the emission band at 360 nm and an increase of a new fluorescence peak around 454 nm. The fluorescent intensity ratio at 454 and 360 nm (I₄₅₄/I₃₆₀) increases linearly with fluoride ion concentration in the range 0.3-8.0 μmol L⁻¹ and the detection limit is 0.19 μmol L⁻¹. The proposed probe shows excellent selectivity toward fluoride ion over other common anions. The method has been successfully applied to the fluoride determination in toothpaste and tap water samples.     

A ratiometric fluorescent chemodosimeter for Cu(II) in water with high selectivity and sensitivity

Coumarin derivative 1 was synthesized as an efficient ratiometric chemodosimeter for the detection of Cu(II) in 99% water/DMSO (v/v) at pH 7.0. Mechanism studies suggested that 1 formed a complex with Cu(II) at 2:1 ratio accompanied by quenching of green fluorescence at 524 nm; when the solution was heated to 50 °C for 30 min, Cu(II)-promoted hydrolysis of coumarin lactone moiety of 1 occurred with bright blue fluorescence at 451 nm emerged. With fluorescence intensity ratio detection at 451 nm and 524 nm, 1 features an excellent sensitivity with the detection limit of 15 nmol L⁻¹ toward Cu(II) and a good selectivity over other metal ions.     

A turn-on fluorescent probe for Au3+ based on rodamine derivative and its bioimaging application

A new fluorescent probe RY was synthesized for the detection of Au³⁺ ions based on a rhodamine B derivative. The fluorescent probe showed good selectivity and sensitivity to Au³⁺ ions. Obvious color and fluorescence changes could be observed with the naked eye while the fluorescent probe reacted with the Au³⁺ ions. The detection limit of the probe was determined to be 36 ppb by the fluorescence titration; the excellent linear relationship suggests that the probe is potentially useful for quantitative detection of Au³⁺ in vitro. We also demonstrated its bioimaging application in both living cells and mice; this was the first time that a fluorescent probe was successfully applied to imaging Au³⁺ in living animals.