ω-对联苯基多亚甲基羧酸4-[5'-对联苯基 二唑基-2']-苄酯的分子内能量传递的研究

合成了几个ω-对联苯基多亚甲基羧酸4-(5'-对联苯基 二唑基-2')-苄酯及其模型化合物2-对甲苯基-5-联苯基-1,3,4- 二唑。测试了它们的紫外吸收光谱和荧光发射光谱, 用稳态荧光光谱方法, 测定了双荧光团化合物的分子内能量传递效率和模型化合物分子间能量传递效率进行了比较, 光谱数据表明分子内能量传递效率可达100%, 另外在相同浓度下测定了双荧光团化合物和模型化合物的磷光光谱, 比较测得的荧光光谱和磷光光谱的强度, 结果相互符合, 同时也测定了给体、受体以及双荧光团化合物的荧光寿命及磷光平均寿命, 根据稳态荧光光谱数据, 计算了能量传递的临界距离R0及能量传递的速率常数kT。     

ω-对联苯基多亚甲基羧酸4-[5'-对联苯基 二唑基-2']-苄酯的分子内能量传递的研究

合成了几个ω-对联苯基多亚甲基羧酸4-(5'-对联苯基 二唑基-2')-苄酯及其模型化合物2-对甲苯基-5-联苯基-1,3,4- 二唑。测试了它们的紫外吸收光谱和荧光发射光谱, 用稳态荧光光谱方法, 测定了双荧光团化合物的分子内能量传递效率和模型化合物分子间能量传递效率进行了比较, 光谱数据表明分子内能量传递效率可达100%, 另外在相同浓度下测定了双荧光团化合物和模型化合物的磷光光谱, 比较测得的荧光光谱和磷光光谱的强度, 结果相互符合, 同时也测定了给体、受体以及双荧光团化合物的荧光寿命及磷光平均寿命, 根据稳态荧光光谱数据, 计算了能量传递的临界距离R0及能量传递的速率常数kT。     

ω-对联苯基多亚甲基羧酸4-[5′-对联苯基噁二唑基-2′]-苄酯的分子内能量传递的研究

继2-(ω-联苯基多亚甲基)-5-联苯基-1,3,4-噁二唑双荧光团化合物的合成及其荧光光谱的测定之后,我们又合成了几个ω-对联苯基多亚甲基羧酸4-(5’-对联苯基噁二唑基-2’)-苄酯及其模型化合物2-对甲苯基-5-联苯基-1,3,4-噁二唑。测试了它们的紫外吸收光谱和荧光发射光谱,用稳态荧光光谱方法,测定了双荧光团化合物的分子内能量传递效率和模型化合物分子间能量传递效率进行了比较。光谱数据表明分子内能量传递效率可达100％。另外在相同浓度下测定了双荧光团化合物和模型化合物的磷光光谱,比较测得的荧光光谱和磷光光谱的强度,结果相互符合。同时也测定了给体、受体以及双荧光团化合物的荧光寿命及磷光平均寿命,根据稳态荧光光谱数据,计算了能量传递的临界距离R_0及能量传递的速率常数k_г。     

牛血清白蛋白@席夫碱双荧光化合物组合构建三输入-双输出分子逻辑电路

基于牛血清白蛋白与邻苯二胺缩二5-氟水杨醛这两种荧光化合物组合的方式设计了一种荧光探针,并采用荧光光谱、同步荧光光谱、三维荧光光谱及分子对接等方法研究它们之间相互作用的机理。实验结果表明,邻苯二胺缩二5-氟水杨醛与牛血清白蛋白之间可以形成稳态复合物,在形成过程中氢键及范德华力起主导作用,且邻苯二胺缩二5-氟水杨醛对牛血清白蛋白的构象会产生影响。此外,在280nm激发下,邻苯二胺缩二5-氟水杨醛与牛血清白蛋白之间可以基于荧光共振能量转移而在350nm及460nm处产生两个荧光发射峰。基于该特征,文章以牛血清白蛋白@邻苯二胺缩二5-氟水杨醛作为分子基逻辑材料,通过不同的金属离子对两个荧光发射峰进行调节,从而成功地构建出三个不同的分子逻辑路。     

双-β-萘甲基二胺及其衍生物的荧光光谱及分子内激发态复合物的形成

我们合成了N,N'-二甲基-二-β-萘甲基乙二胺(Ⅰ),N,N'-二甲基-二-β-萘甲基丙二胺(Ⅱ),N,N'-二-β-萘甲基哌嗪(Ⅲ)三个化合物,并测定了它们的荧光光谱。结果表明,它们既能形成分子内激基缔合物(excimer),又能形成分子内激基复合物(exciplex),与溶剂极性有关。在极性较大的溶剂如乙腈和甲醇中,由于激基复合物几乎完全解离因而不发射荧光,这时观察到的荧光峰蓝移而且强度增加,可以认为,这是激基缔合物存在的证明。这三个化合物的分子内激基缔合物形成的难易程度按Ⅱ>Ⅰ>Ⅲ的次序依次递降。     

具有聚集诱导发光及机械变色特性的含Au(Ⅰ)化合物的设计、合成及性质研究

设计合成了两个含Au(I)的化合物1和2,利用核磁共振(NMR)、红外光谱(IR)、元素分析等对其结构进行了表征.通过对其在二甲亚砜(DMSO)/水体系或N,N-二甲基甲酰胺(DMF)/水体系中荧光光谱的研究,显示其在纯有机溶剂中没有荧光,而在混合体系中,水含量达到一定程度后,其荧光会显著增强.这表明化合物1和2均具有明显的聚集诱导发光性质.对化合物1和2的固体粉末进行研磨,其固体荧光会显著增强,而且将研磨后的样品暴露在有机溶剂蒸汽中一段时间后,荧光强度又会恢复到原来的强度.这表明化合物1和2均具有机械变色的性质.通过它们的X射线粉末衍射(XRD)测试发现,这两个化合物在研磨前后分子堆积态实现了从晶态到无定形态的转变.因此这两个化合物具有成为新型智能材料的潜质.     

1,5-二芳基-3-(2-羟基-4,6-二甲氧基苯基)-2-吡唑啉的合成及氟离子荧光探针行为

设计合成了8个1,5-二芳基-3-(2-羟基-4,6-二甲氧基苯基)-2-吡唑啉化合物4a~4h. 它们的结构经由IR、1H NMR、MS和元素分析确认. 测定了它们的紫外光谱和荧光光谱, 研究了它们对氟离子的选择性识别作用, 发现化合物4a,4c和4d均可选择性地识别氟离子, 其中4a和4c作为识别氟离子的荧光探针, 受常见离子干扰较小, 选择性较高.     

3,6-二(3-苯基-1,3-丙二酮基)-9-乙基咔唑的合成、光谱性质与量子化学研究

咔唑分子经SN1烷基化、Friedle-crafts双乙酰化和Claisen缩合3步反应,合成了一种新颖的双β-二酮化合物9-乙基-3,6-二(3-苯基-1,3-丙二酮基)咔唑,对其结构进行了元素分析、IR、1H NMR和MS表征.研究了中间体和目标化合物的吸收光谱性质,采用密度泛函理论在B3LYP/6-31G*水平上对目标化合物基态结构进行优化,运用含时密度泛函理论在相同水平上计算了吸收光谱数据,从微观上分析了化合物的电子跃迁行为.     

3,6-二(蒽醌-2-乙烯基)-N-乙基咔唑的合成及光谱性质研究

利用N-乙基咔唑和2-甲基蒽醌合成了一种A-π-D-π-A分子内电荷转移型化合物3,6-二(蒽醌-2-乙烯基)-N-乙基咔唑,并对该化合物的光化学和光物理行为进行了研究。荧光光谱表明,该化合物的发光行为对溶剂的极性非常敏感,随着溶剂极性的增大,其荧光最大发射峰有明显红移,并在强极性溶剂乙腈中出现了双荧光现象。该化合物的激发态和基态的偶极矩差值△μ为3.014D,发生了从给体(咔唑基)的N原子到分子两端受体(蒽醌)的羰基的分子内电荷转移。     

1,3,4-噁二唑键联二芳基乙烯化合物的合成及性质

将1,3,4-噁二唑基团引入二芳基乙烯分子中, 合成了2种新的二芳基乙烯类光致变色化合物1-氰基-2-(2H-5-苯基-1,3,4-噁二唑)-1,2-二(2,4,5-三甲基-3-噻吩)乙烯(3)和1,4-二{[1-氰基-2-(2H-5-苯基-1,3,4-噁二唑)-1,2-二(2,4,5-三甲基-3-噻吩)乙烯]-1,3,4-噁二唑}苯(4). 通过IR, NMR, MS和元素分析对化合物进行了结构表征, 并研究了其UV-Vis吸收、荧光发射、动力学特性和抗疲劳性质. 实验结果表明, 化合物[STHZ]3[STBZ]和[STHZ]4[STBZ]具有良好的光致变色性质, 光致变色闭环反应为零级反应, 开环反应为一级反应.     

Syntheses and Optoelectronic Properties of Planar Compounds 3,7‐diaryl‐1,5,2,4,6,8‐dithiotetrazocine

Planar molecules 3,7‐diaryl‐1,5,2,4,6,8‐dithiotetrazocines would be potential acceptor materials of organic solar cell because of their containing SN units. One‐pot synthetic procedures of 3,7‐diaryl‐1,5,2,4,6,8‐dithiotetrazocine compounds are developed to improve their yields up to 2.1–5.9 times as much as those in literatures. The geometries of title compounds were optimized by the density functional theory calculations. Their optoelectronic properties were studied by ultraviolet and cyclic voltammetry spectra and fluorescence quenching experiments. The highest occupied and lowest unoccupied molecular orbital energy level values show that these compounds are suitable to be employed as acceptor materials for developing bulk heterojunction organic solar cells with high open circuit voltages. Emission fluorescence of poly(3‐hexylthiophene) at excited state in dichloromethane was quenched by addition of title compound. Therefore, these compounds used as acceptor materials could exhibit good mobility.     

Metal‐Free Facile Synthesis of Multisubstituted 1‐Aminoisoquinoline Derivatives with Dual‐State Emissions

Although isoquinoline is a good traditional fluorescent structural unit, most of its derivatives emit fluorescence in solution and a few of them can emit solid‐state fluorescence as well. Herein, a series of multisubstituted 1‐aminoisoquinoline derivatives were synthesized by a simple reaction of a readily available 4H‐pyran derivative and secondary amines. The reaction had advantages of metal‐free, mild conditions, simple operation, and good yields, which was realized by a ring‐opening and sequential ring‐closing mechanism. These 1‐aminoisoquinoline derivatives were found to exhibit interesting dual‐state emissions. In the solution, they emitted strong blue fluorescence at about 458 nm. In the solid state, they emitted solid‐state blue fluorescence at 444–468 nm with high fluorescence quantum yields of 40.3–98.1%. Crystal structural analyses indicated that solid‐state emissions of these compounds originated from twisted molecular conformations and the resultant loose stacking arrangements. Furthermore, their solid‐state fluorescence wavelengths were demonstrated to depend on molecular conformations rather than stacking arrangements. The discovery of these 1‐aminoisoquinolines with multiple reaction sites provides new possibilities for the development of solid‐state fluorescent materials based on the traditional isoquinoline skeleton.     

Synthesis and Fluorescent Properties of 2‐Arylamino‐5‐(3‐Aryl‐1‐Phenyl‐Pyrazol‐4‐Yl)‐1,3,4‐Thiadiazoles

A series of novel pyrazolyl‐substituted 1,3,4‐thiadiazole derivatives ( 6a‐6d, 7a‐7d, 8a‐8d ) were prepared by cyclization of the intermediate 3‐aryl‐l‐phenyl‐pyrazol‐4‐ylformaldehyde 4′‐phenylthiosemicarbazones with 0.5 M ferric chloride solution. The structures of the new compounds were confirmed by IR, ¹H NMR and elemental analysis. Simultaneously, the compounds were detected by fluorescence spectrophotometer and had preferable fluorescence activity.     

Preparation and Characterization of Substituted 3‐Benzothiazol‐2‐Ylcoumarins

A series of substituted 3‐benzothiazolylcoumarins was prepared from condensation of 2‐hydroxy‐benzaldehyde and 2‐cyanomethylbenzothiazole to investigate the effect of the nature and position of substituents on their absorption and fluorescent behavior. Compounds with a substituent containing a heteroatom which attached at the C6 position showed a split broad absorption band. Solutions of these compounds in various solvents exhibited brilliant blue fluorescence. The emission intensity for compounds with an alkoxy group at the C6 or C7 position in DMF was approximately 7‐ and 15‐fold higher than for the corresponding precursor and quinine sulfate solution, respectively. These compounds also exhibit high thermal stability in solid state.     

Synthesis of 10‐amino‐9‐aryl‐2,3,4,5,6,7,9,10‐octahydroacridine‐1,8‐dione derivatives

A series of novel 10‐amino‐9‐aryl‐2,3,4,5,6,7,9,10‐octahydroacridine‐1,8‐dione derivatives 4 were synthesized by hydrazine or phenylhydrazine and 9‐aryl‐1,8‐dioxo‐2,3,4,5,6,7,9‐heptahydroxanthene derivatives 3 , which were prepared by 5‐substituted‐1,3‐cyclohexanedione 1 and aromatic aldehydes 2 in the presence of concentrated H₂SO₄ as a catalyst in water. The structures of all compounds were characterized by IR, MS, ¹H‐NMR, and elemental analysis, and the title compounds possess good fluorescence properties. J. Heterocyclic Chem., (2012).     

Design and Synthesis of 2‐(5‐Phenylindol‐3‐yl)benzimidazole Derivatives with Antiproliferative Effects towards Triple‐Negative Breast Cancer Cells by Activation of ROS‐Mediated Mitochondria Dysfunction

Benzimidazole derivatives are widely studied because of their broad‐spectrum biological activity, such as antitumor properties and excellent fluorescence performance. Herein, two types of 2‐(5‐phenylindol‐3‐yl)benzimidazole derivatives ( 1 a – 1 h and 2 a – 2 e ) were rationally designed and synthesized. When these compounds were investigated in vitro anti‐screening assays, we found that all of them possessed antitumor effect, in particular compound 1 b , which showed an outstanding antiproliferative effect on MDA‐MB‐231 cells (IC₅₀≈2.6 μm ). A study of the drug action mechanisms in cells showed that the antitumor activity of the compounds is proportional to their lipophilicity and cellular uptake; the tested compounds all entered the lysosome of MDA‐MB‐231 cells and caused changes in the levels of reactive oxygen species (ROS), and then caused mitochondrial damage. Apparent differences in the ROS levels for each compound suggest that the lethality of these compounds towards MDA‐MB‐231 cells is closely related to the ROS levels. Taken together, this study not only provides a theoretical basis for 2‐(5‐phenylindol‐3‐yl)benzimidazole anticarcinogens but also offers new thinking on the rational design of next‐generation antitumor benzimidazole derivatives.     

Tunable Dual Fluorescence of 3‐(2,2′‐Bipyridyl)‐Substituted Iminocoumarin

3‐(2,2′‐Bipyridyl)‐substituted iminocoumarin molecules (compounds 1 and 2 ) exhibit dual fluorescence. Each molecule has one electron donor and two electron acceptors that are in conjugation, which leads to fluorescence from two independent charge transfer (CT) states. To account for the dual fluorescence, we subscribe to a kinetic model in which both CT states form after rapid decays from the directly accessed S₁ and S₂ excited states. Due to the slow internal conversion from S₂ to S₁, or more likely the slow interconversion between the two subsequently formed CT states, dual emission is allowed to occur. This hypothesis is supported by the following evidence: 1) the emission at short and long ends of the spectrum originates from two different excitation spectra, which eliminates the possibility that dual emission occurs after an adiabatic reaction at the S₁ level. 2) The fluorescence quantum yield of compound 2 grows with increasing excitation wavelength, which indicates that the high‐energy excitation elevates the molecule to a weakly emissive state that does not internally convert to the low‐energy, highly emissive state. The intensity of the two emission bands of 1 is tunable through the specific interactions between either of the two electron acceptors with another species, such as Zn²⁺ in the current demonstration. Therefore, the development of ratiometric fluorescent indicators based on the dual‐emitting iminocoumarin system is conceivable. Further fundamental studies on this series of compounds using time‐resolved spectroscopic techniques, and explorations of their applications will be carried out in the near future.     

BF2‐Chelate Complexes of 6‐(4‐Iodophenyl)‐2,3,4,8,9,10‐hexamethyldipyrrin and 2‐(4‐Iodobenzoyl)‐3,4,5‐trimethylpyrrole: Fluorescent Dyes with a Chemical Anchor Group

The one‐pot condensation/coordination reaction of 4‐iodobenzoylchloride, 2,3,4‐trimethylpyrrole and BF₃ × Et₂O yields the BF₂ chelate complexes of the 1:1 condensation product 2‐(4‐iodobenzoyl)‐3,4,5‐trimethylpyrrole and of the 1:2 product 6‐(4‐iodophenyl)‐2,3,4,8,9,10‐hexamethyldipyrrin, as separable compounds in 6 and 38 % yield, respectively. Both new boron derivatives are fluorescent already upon exitation with ambient light. While the fluorescence quantum yield of the benzoyl derivative is very low, this value is significantly higher for the related boron dipyrrin (BODIPY) derivative. Single crystal X‐ray diffraction studies of both compounds reveal that the reason for these deviating physical properties are structural in nature. For the BODIPY an essentially flat structure of the fluorophor has been established, in addition to restricted rotation of the 4‐iodophenyl substituent, so that no conformational dynamic facilitates radiationless deactivations. The 1:1 condensation product on the other hand allows a fast equilibration of the photophysical exitation by dynamic processes and therefore exhibits a low fluorescence quantum yield. Both luminophores contain an iodoaryl moiety with potential uses for further functionalization and bioconjugation.     

Combining the Advantages of Tetrazoles and 1,2,3‐Triazoles: 4,5‐Bis(tetrazol‐5‐yl)‐1,2,3‐triazole, 4,5‐Bis(1‐hydroxytetrazol‐5‐yl)‐1,2,3‐triazole,and their Energetic Derivatives

In the development of new energetic materials, the main challenge is the combination of high energy content with chemical and mechanical stability, two properties that are often contradictory. In this study, the syntheses and comprehensive characterizations of 4,5‐bis(tetrazole‐5‐yl)‐1,2,3‐triazole and the novel 4,5‐bis(1‐hydroxytetrazole‐5‐yl)‐1,2,3‐triazole, as well as their energetic properties, are presented, combining the advantages of the more energetic tetrazole and the more stable 1,2,3‐triazole rings. Nitrogen‐rich salts of both compounds were synthesized to investigate their detonation performances and combustion behavior calculated by computer codes for potential application in erosion‐reduced gun propellant mixtures due to their high nitrogen content. The structures of several of the compounds were studied by single‐crystal X‐ray diffraction and, especially in the case of 4,5‐bis(tetrazol‐5‐yl)‐1,2,3‐triazole, revealed the site of deprotonation.     

An Efficient Synthesis of 6′‐methyl‐1'H‐spiro[indoline‐3,4′‐pyrimidine]‐2,2′(3'H)‐dione Derivatives

The reactions of isatins, urea and 1‐(piperidin‐1‐yl)butane‐1,3‐dione or 1‐morpholinobutane‐1,3‐dione have been developed for the preparation of spiroheterocycles compounds. It was found these reactions could be given higher yields and required shorter time in our process. In this synthesis, some useful groups, such as pyridyl and morpholinyl were introduced into the structures of the products. The compounds were confirmed by IR, ¹H NMR, ¹³C NMR, and HRMS. Else, compounds 4i and 4r were additionally confirmed by X‐ray diffraction analysis. The other advantages of this procure were simple handling, high yields, and wide range substrates.