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91.
Four coordination polymers based on 4′-(2H-tetrazol-5-yl)biphenyl-4-carboxylic acid (H2TBPC), [Zn(μ3-TBPC)(H2O)]n (1), [Zn(μ3-TBPC)(Me2NH)]n (2), [Cd(μ3-TBPC)(bpy)]n (bpy = 4,4′-bipyridine, 3), and [Cd(μ4-TBPC)(H2O)]n (4), were constructed under hydrothermal conditions. The compounds are composed of M2(TBPC)2 binuclear ring as a building block. In 1–3, the binuclear rings are interconnected to three different 2-D networks with the same (4·82) topology. In 4, the binuclear rings are arranged into a 3-D framework with PtS-type topology. The results revealed that the structural diversity is mainly attributed to the coordination geometries of metal ion, the coordination modes of TBPC2?, and the auxiliary ligand. The thermal stabilities and luminescent properties of 1–4 have also been studied. 相似文献
92.
Anionic Oligothiophenes Compete for Binding of X‐34 but not PIB to Recombinant Aβ Amyloid Fibrils and Alzheimer's Disease Brain‐Derived Aβ
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Marcus Bäck Hanna Appelqvist Harry LeVine III K. Peter R. Nilsson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(51):18335-18338
Deposits comprised of amyloid‐β (Aβ) are one of the pathological hallmarks of Alzheimer's disease (AD) and small hydrophobic ligands targeting these aggregated species are used clinically for the diagnosis of AD. Herein, we observed that anionic oligothiophenes efficiently displaced X‐34, a Congo Red analogue, but not Pittsburgh compound B (PIB) from recombinant Aβ amyloid fibrils and Alzheimer's disease brain‐derived Aβ. Overall, we foresee that the oligothiophene scaffold offers the possibility to develop novel high‐affinity ligands for Aβ pathology only found in human AD brain, targeting a different site than PIB. 相似文献
93.
通过设计合理的微腔结构,制备了基于绿光染料C545t、黄光染料Rubrene、红光染料DCJTB的3种顶发射有机电致发光器件。研究了不同发光染料对顶发射器件的光谱的影响。研究表明,微腔结构对光谱具有窄化作用。绿光、黄光器件的发光峰波长并未随视角增大而明显变化,体现出良好的光谱角度性,而红光器件却出现了明显的光谱蓝移现象。绿光器件的最大功率效率为8.7 lm/W,当电流密度为45 m A/cm2时,亮度能达到7 205 cd/m2;黄光器件的电流效率最大值为11.5 cd/A,当电流密度为48 m A/cm2时,亮度可达到3 770 cd/m2;红光器件的电流效率最大能达到3.54 cd/A,当电流密度为50 m A/cm2时,可获得1 358 cd/m2的亮度。采用合适的发光材料以及合适的器件结构,不仅可以提高顶发射器件的色纯度及发光效率,还可以改善器件发光光谱的角度依赖性。 相似文献
94.
95.
沸石基纳米材料的水热分散法制备及其发光 总被引:4,自引:0,他引:4
用水热分散法,通过进行分步化学反应,在沸石分子筛的孔道中简便有效地制备了沸石基纳米发光材料.样品的发光表现出纳米粒子的量子尺寸效应 相似文献
96.
以表面活性剂十二烷基硫酸钠为均匀分散剂,通过液相与固相相结合的方法制备了Y2O2S∶Eu3+,Mg2,Ti4+红色长余辉材料.采用X射线衍射(XRD)、扫描电镜(SEM)、激发与发射光谱、热释光谱等手段对材料进行了表征.研究结果表明,与高温固相法相比,样品的最低合成温度与最佳合成温度均降低了200~300℃,其发光特性没有改变,表面活性剂的添加影响了样品的形貌.同时,对表面活性剂引入后,Y2O2S∶Eu3+,Mg2+,Ti4+的生长机制和发光机理进行了讨论. 相似文献
97.
Tristan A. Geervliet Ionela Gavrila Giuseppe Iasilli Francesco Picchioni Andrea Pucci 《化学:亚洲杂志》2019,14(6):877-883
This study reports for the first time the use of bio‐based alternatives for PMMA as host matrix for luminescent solar concentrators (LSCs). Notably, two types of renewable polyesters were synthesized in varying molar ratios via a two‐step melt‐polycondensation reaction with dibutyl tin oxide as catalyst. The first is a homopolymer of diethyl 2,3:4,5‐di‐O‐methylene galactarate (GxMe) and isosorbide (IGPn), and the second is a random copolymer of GxMe with 1,3‐propanediol and dimethyl terephthalate (GTPn). The two polyesters were found to be optically transparent, totally amorphous with a Tg higher than 45 °C and temperature resistance comparable to PMMA. Lumogen Red (LR) and an aggregation‐induced emission (AIE) fluorophore, TPETPAFN, were utilized as fluorophores and the derived thin polymer films (25 μm) were found highly homogeneous, especially for those prepared from GTPn, possibly due to the presence of compatibilizing terephthalate units in the matrix composition and the higher molecular weight. The spectroscopic characterization and the optical efficiency determination (ηopt) evidenced LSCs performances similar or superior to those collected from LR/PMMA thin films. Noteworthy, ηopt of 7.7 % and 7.1 % were recorded for the GTPn‐based matrix containing LR and TPETPAFN, respectively, thus definitely supporting the bio‐based polyesters as renewable and highly fluorophore‐compatible matrices for high‐performance LSCs. 相似文献
98.
Two new three‐dimensional (3D) LnIII metal‐organic frameworks (MOFs) were designed and successfully obtained via a solvothermal reaction between lanthanide(III) nitrates and a semi‐flexible carbazole tetracarboxylate acid linker as a high‐performance chromophore. 1 and 2 possess porous 3D networks with channels along the a axis, and more importantly, they show a highly sensitive and selective fluorescence quenching response to Fe3+ and CrVI anions. The sensing mechanism investigation revealed that the weak interactions of Fe3+ with nitrogen atoms of carbazole and deprotonated carboxylic acids protruding into the pores of MOFs quenched the luminescence of 1 and 2 effectively. In addition, the competition absorption also played an important role in the luminescence quenching detection of Fe3+ based on 1 , and CrVI anions based on 1 and 2 . Therefore, 1 and 2 represent an alternative example of regenerable luminescence based sensors for the quantitative detection of Fe3+ and CrVI anions. 相似文献
99.
Huili Ma Anqi Lv Lishun Fu Shan Wang Zhongfu An Huifang Shi Wei Huang 《Annalen der Physik》2019,531(7)
Purely organic materials with room‐temperature phosphorescence (RTP) have attracted a growing interest for their potential applications in biological imaging, digital encryption, optoelectronic devices, and so on. To date, many strategies have succeeded in designing efficient organic RTP materials by overcoming the spin‐forbidden transition between singlet and triplet states. However, the underlying mechanisms of RTP still remain ambiguous. Such spin prohibition in phosphorescence are clarified, herein, from the perspective of perturbation theory, helping to understand the intrinsic relationship among various phosphorescence parameters, like phosphorescence efficiency, lifetime, intersystem crossing rate, as well as radiative and nonradiative rates. Taking into consideration the recent progress in organic RTP materials, these factors are further illustrated by a selection of the most relevant molecules. In addition, some novel RTP phenomena are also reviewed, thus providing an excellent guideline to constructing efficient RTP materials. 相似文献
100.
四(4-苯乙烯基)硅烷(TVBS)和溴代二苯乙烯基吡啶(Br-DSP)通过Heck偶联反应构筑以共价键连接的具有pH响应的新型多孔材料. 材料具有良好的孔性能和热稳定性能, 其比表面积为467 m2·g-1, 孔体积为0.41 cm3·g-1. 所得的多孔材料在273 K/760 mmHg条件下的CO2吸附量为2.96 wt%. 二苯乙烯基吡啶(DSP)单元的引入, 使多孔材料具有优异的荧光性能, 其中N原子作为质子化中心, 使材料具有pH响应性. 在固体状态下, 材料的荧光最大发射波长在526 nm; 在pH=1.00~4.50范围内, 材料的荧光最大发射波长和相应的pH值成线性关系, 表明该材料可用于酸性溶液的精确地快速检测. 相似文献