基于1,3,6,8-四甲基咔唑热活化延迟荧光材料的合成及发光性质

以1,3,6,8-四甲基咔唑(TMCz)为给体,1,3,4-二唑(OXD)和1,3,4-噻二唑(THD)分别为受体,设计合成了两例发光材料2,5-双{4-[9-(1,3,6,8-四甲基咔唑基)]-苯基}-1,3,4-二唑(TMCz-OXD)和2,5-双{4-[9-(1,3,6,8-四甲基咔唑基)]-苯基}-1,3,...     

4-氮杂芴-9-酮衍生物的合成及发光性质

以4-氮杂芴-9-酮(IP)为电子受体,咔唑(Cz)为电子供体,通过调节Cz在IP上的取代位置合成了4例荧光染料,即IP-6-Ph Cz、IP-7-PhCz、IP-8-PhCz和IP-9-PhCz。利用紫外吸收光谱、荧光发射光谱、电化学分析等对所得4例荧光染料的光致发光、电致发光以及电化学性质进行了测试。结果表明,IP-6-Ph Cz和IP-9-PhCz分别实现了45.3°和51.8°的大扭曲角,其单重态-三重态能级差(ΔEST)分别为0.32和0.28eV,表现出热活化延迟荧光(TADF)特征,而IP-7-PhCz和IP-8-PhCz仅是普通的荧光染料。其中,IP-7-PhCz的光致发光量子产率(PLQY)为29%,电致发光的最大外量子效率为2.8%。     

含咔唑基团芘类荧光材料的合成与发光性质

以1-溴芘、1,6-二溴芘和9-对乙炔苯基咔唑为原料,通过Sonogashira偶联反应合成了1-（4-（9-咔唑）苯乙炔基）芘和1,6-二（4-（9-咔唑）苯乙炔基）芘两种荧光分子。经熔点、核磁共振氢谱以及元素分析等结构表征,对中间体和目标产物的紫外-可见吸收、荧光发射以及结构与性质之间的构效关系进行了研究。通过结构修饰,可有效调节此类分子的吸收及发射性质。当芘单元作为中心电子受体,以4-苯乙炔基为桥连基,引入咔唑基团作为电子给体时,其分子共轭程度、结构刚性和分子内电荷转移能力显著提高。相对于D-π-A结构的单取代化合物,双取代D-π-A-π-D结构分子的最大发射峰由422 nm红移至446 nm,荧光量子效率由0.64提升至1.08。该类化合物可作为高效的蓝光荧光材料,应用于有机光致/电致发光材料以及有机发光二极管等领域。     

热活性型延迟荧光材料的研究进展

有机电致发光二极管（OLED）在全彩色平板显示和固态照明领域具有广泛的应用而倍受关注。在电场激发下,单重态激子与三重态激子的比值为1∶3。传统的荧光材料只能利用单重态激子发光,内部量子效率（IQE）最高为25%。热活性型延迟荧光（TADF）材料可将三重态激子反系间跨越（RISC）到单重态能级而发出延迟荧光,理论上内部量子效率可达100%。设计TADF材料的关键在于分子要同时满足高荧光量子产率和小的第一激发单重态与第一激发三重态能级差（ΔE_ST）。综述了近几年TADF材料的研究进展,重点介绍了TADF材料的设计思想和器件性能。     

含咔唑基团芘类荧光材料的合成与发光性质

以1-溴芘、1,6-二溴芘和9-对乙炔苯基咔唑为原料,通过Sonogashira偶联反应合成了1-[4-(9-咔唑)苯乙炔基]芘和1,6-二[4-(9-咔唑)苯乙炔基]芘两种荧光分子。经熔点、核磁共振氢谱以及元素分析等结构表征,对中间体和目标产物的紫外-可见吸收、荧光发射以及结构与性质之间的构效关系进行了研究。通过结构修饰,可有效调节此类分子的吸收及发射性质。当芘单元作为中心电子受体,以4-苯乙炔基为桥连基,引入咔唑基团作为电子给体时,其分子共轭程度、结构刚性和分子内电荷转移能力显著提高。相对于D-π-A结构的单取代化合物,双取代D-π-A-π-D结构分子的最大发射峰由422 nm红移至446 nm,荧光量子效率由0.64提升至1.08。该类化合物可作为高效的蓝光荧光材料,应用于有机光致/电致发光材料以及有机发光二极管等领域。     

含1,3,4-(噁)二唑环的有机电致发蓝光材料及器件研究进展

1,3,4–口恶 二唑环是一个具有高电子亲和势和空穴阻挡作用的基团,含该基团的化合物是一类具有良好电子传输功能的有机电致发光材料。近年来含1,3,4–口恶 二唑环化合物发蓝光的有机电致发光材料已成为材料科学研究的一个热点。综述了含1,3,4–口恶 二唑环的小分子和高分子发蓝光的有机电致发光材料的分子结构、性能及其器件性能的研究现状,并对提高这类材料性能的分子设计方面作了简要的展望。     

基于蒽醌和三苯胺的红色延迟荧光材料

通过Suzuki反应,在电子受体基团蒽醌（AQ）的α-位引入电子给体基团三苯胺（TPA）,合成了三种红色延迟荧光材料(1-TPA-AQ,1,4-2TPA-AQ和1,8-2TPA-AQ),目标化合物的结构经核磁、质谱和元素分析确证。通过理论计算、紫外-可见（UV-Vis）吸收光谱、荧光发射光谱和循环伏安（CV）测试,系统地考察了三种化合物的光物理和电化学性质。结果表明,三种化合物的单线态-三线态能级差(ΔEST)分别为0.08,0.09和0.06 eV,最高占有分子轨道（HOMO）能级分别为-5.26,-5.23和-5.27 eV,最低未占分子轨道（LUMO）能级分别为-3.14,-3.10和-3.10 eV。 1-TPA-AQ,1,4-2TPA-AQ和1,8-2TPA-AQ在薄膜中的荧光发射波长分别为648,649和636 nm,延迟荧光寿命分别1.6,2.6和2.1 μs ,三者均可作为红色延迟荧光材料。     

含噁二唑-三苯胺基的双光子化合物合成及光谱研究

为了开发高强度的有机电致发光材料,合成了一种含空穴传输基团三苯胺、电子传输基团1,3,4-噁二唑,所含的三苯胺和1,3,4-噁二唑基用吡啶基链接,相互之间存在共轭,可形成分子内的偶极,有利于提高载流子传输的性能。用红外光谱、质谱、核磁共振谱和元素分析对合成化合物进行了结构表征,用荧光光谱仪对它们的荧光性能进行了测试,所合成化合物的荧光性能较好,荧光发射波长为446 nm,并且荧光量子产率最高能达到0.42。     

含噁二唑类有机电致发光材料的研究进展

有机电致发光器件(OLED)具有视角宽、功耗低、响应速度快、发光亮度和发光效率高、能实现全色显示等优点,备受科学界和产业界的广泛重视。特别是自从1987年Tang首次报道了工作电压低、发光亮度高的OLED以来,其研究工作取得了更快速地发展。近十余年里,已经逐渐成为多学科交叉的具有高技术含量的前沿课题。含1,3,4-噁二唑环的-聚合物作为一种新型的具有电子传输功能的有机电致发光材料在近10年的研究中引起了人们的极大关注。由于1,3,4-噁二唑环是一个具有高电子亲和势和空穴阻挡作用的基团,因此含该基团的化合物是一类具有良好电子传输功能的有机电致发光材。     

新型空穴传输材料N,N＇-二苯基-N,N＇-二（3-甲苯基）-4,4＇-联萘胺的合成、薄膜发光与能级比较

将有机电致发光中最常用的空穴传输材料N,N＇-二苯基-N,N＇-二（3-甲苯基）-4,4＇-联苯胺（TPD）中的联苯以联萘代替,合成了新型空穴传输材料N,N＇-二苯基-N,N＇-二（3-甲苯基）-4,4＇-联萘胺（PMPN）.与TPD在熔点、薄膜发光、量子效率和电化学行为上进行了比较.PMPN比TPD（m.p.175）有稍低的熔点、稍高的电离势,更高的薄膜荧光量子效率.联萘的引入可以增大体系的共轭作用,对载流子传输有益.通过构效关系的分析,可以对进一步合成高性能空穴材料进而得到高性能的有机电致发光器件有所借鉴.     

Synthesis,spectroscopy, and electrochemical investigation of new conjugated polymers containing thiophene and 1,3,4-thiadiazole in the main chain

Novel photoluminescent donor–acceptor poly(p-phenylenevinylene)-type conjugated polymers containing thiophene and 1,3,4-thiadiazole units in the main chain were synthesized from 2,5-bis(5-bromomethyl-2-thienyl)-1,3,4-thiadiazole and 1,3/1,4-benzenedialdehyde by Wittig–Horner reaction. The synthesized polymers were characterized by the use of thermal analysis and spectroscopic (infrared, UV-visible absorption, and photoluminescence) measurement. The resultant material exhibited bluish green, green, and orange fluorescence in their solution and thin film and solid forms, respectively. The redox property of the polymers has also been studied by cyclic voltammetry. The optical and electrochemical studies reveal that these novel polymers are new promising materials for the development of efficient polymer light-emitting diodes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Electroluminescence from polyvinylcarbazole films: 4. Electroluminescence using higher work function cathodes

Following the previous demonstration of electroluminescence emission from polyvinylcarbazole (PVCz) films having caesium cathodes, the possibility of using less chemically reactive higher work function cathodes was studied. It is shown that this can in principle be accomplished by the use of suitable electron-accepting additives in the PVCz films and a range of cyanobenzene molecules was used for this purpose. The fluorescent properties of the exciplexes and exterplexes inevitably formed between the cyanobenzene acceptors and the carbazole donor groups of the PVCz were investigated in order to determine the most suitable additives. Acceptor anions and carbazole cations in PVCz films were observed spectroscopically at low temperatures as was their recombination luminescence on subsequent warming. Finally, electroluminescence was observed from PVCz films containing cyanobenzene additives and using cathodes of barium or calcium.     

以芳香硫醚为桥链的三体化合物的荧光分子开关性能

将一些发色团分子组装成具有特定功能的分子器件,是近年来随超分子化学和分子信息科学兴起而十分活跃的领域［１］,其中具有逻辑功能的光控开关器件是下一代分子计算机的核心,它们可在分子水平实现信息的存储和数据的处理、传输［２］．国内外这方面的研究主要有顺反异...     

Rise-Time of FRET-Acceptor Fluorescence Tracks Protein Folding

Uniform labeling of proteins with fluorescent donor and acceptor dyes with an equimolar ratio is paramount for accurate determination of Förster resonance energy transfer (FRET) efficiencies. In practice, however, the labeled protein population contains donor-labeled molecules that have no corresponding acceptor. These FRET-inactive donors contaminate the donor fluorescence signal, which leads to underestimation of FRET efficiencies in conventional fluorescence intensity and lifetime-based FRET experiments. Such contamination is avoided if FRET efficiencies are extracted from the rise time of acceptor fluorescence upon donor excitation. The reciprocal value of the rise time of acceptor fluorescence is equal to the decay rate of the FRET-active donor fluorescence. Here, we have determined rise times of sensitized acceptor fluorescence to study the folding of double-labeled apoflavodoxin molecules and show that this approach tracks the characteristics of apoflavodoxinʼs complex folding pathway.     

含噻吩环1,2,4-噁二唑类衍生物的合成及光电性能

以硫代二甘酸和取代苯甲腈为原料,经酯化、环化、酸化等反应合成了2,5-双[3-苯基-1,2,4-噁二唑-5-基]-3,4-二丁氧基噻吩衍生物,通过1HNMR、FTIR和元素分析进行了结构表征,并考察了该系列化合物的紫外-可见吸收光谱、荧光发射光谱及电化学性质。该系列化合物紫外吸收出现在240～250nm和320～350nm两个波段;荧光发射峰位于395～401.5nm,且随苯环上取代基供电子性的增强而规律性红移;循环伏安测定结果表明,该系列化合物中ⅧA、ⅧB、ⅧC和ⅧF具有高于常用电子传输材料2-(4-联苯基)-5-对叔丁基苯基-1,3,4-噁二唑(PBD)的电子亲和势,因而该类化合物的研究,对设计小分子类电致发光材料有重要意义。     

Novel poly(3,4‐dialkoxythiophene)s carrying 1,3,4‐oxadiazolyl‐biphenyl moieties: synthesis and nonlinear optical studies

Two new donor–acceptor types of polymer, poly{2‐(biphenyl‐4‐yl)‐5‐[3,4‐dialkoxy‐5‐(1,3,4‐oxadiazol‐2‐yl)thiophen‐2‐yl]‐1,3,4‐oxadiazole}s, were synthesized starting from 2,2′‐sulfanediyldiacetic acid and diethyl ethanedioate through multi‐step reactions. The polymerization was carried out via the polyhydrazide precursor route. The optical and charge‐transporting properties of the polymers were investigated using UV‐visible and fluorescence emission spectroscopic and cyclic voltammetric studies. The polymers showed bluish‐green fluorescence in solutions. The electrochemical band gaps of the polymers were determined to be 2.16 and 2.22 eV. The nonlinear optical properties of the polymers were investigated at 532 nm using the single‐beam Z‐scan technique with nanosecond laser pulses. The polymers showed strong optical limiting behaviour due to effective three‐photon absorption. The values of the three‐photon absorption coefficients for the polymers were found to be 9 × 10^?24 and 17 × 10^?24 m³ W^?2, which are comparable to those of good optical limiting materials. Copyright © 2010 Society of Chemical Industry     

Nonlinear optical studies on new conjugated poly{2,2l‐(3,4‐ dialkoxythiophene‐2,5‐diyl) bis[5‐(2‐thienyl)‐1,3,4‐oxadiazole]}s

Three new donor–acceptor type poly{2,2^l‐(3,4‐ dialkoxythiophene‐2,5‐diyl)bis[5‐(2‐thienyl)‐1,3,4‐oxadiazole]}s ( P1, P2, and P3 ) were synthesized starting from thiodiglycolic acid and diethyl oxalate through multistep reactions. The polymerization was carried out using chemical polymerization technique. The optical and charge‐transporting properties of the polymers were investigated by UV‐visible, fluorescence emission spectroscopic and cyclic voltammetric studies. The polymers showed bluish‐green fluorescence in solutions. The electrochemical band gaps were determined to be 2.03, 2.09, and 2.17 eV for P1 , P2, and P3, respectively. The nonlinear optical properties of new polymers were investigated at 532 nm using single beam Z‐scan and degenerate four‐wave mixing (DFWM) techniques with nanosecond laser pulses. The polymers exhibited strong optical limiting behavior due to “effective” three‐photon absorption. Values of the effective three‐photon absorption ( 3PA ) coefficients, third‐order nonlinear susceptibilities (χ⁽³⁾), and figures (F) of merit were calculated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis,Structural Characterization,Spectroscopic Properties,and Theoretical Investigations of Aminoacridine Derivatives

Synthesis of four N-(heterocyclic)-9-aminoacridine derivatives was investigated. The synthesized compounds, N-thiazolyl-9-aminoacridine (AC1), N-(1,3,4-thiadiazolyl)-9-aminoacridine (AC2), N-(5-methyl-1,3,4-thiadiazolyl)-9-aminoacridine (AC3), and N-(5-phenyl-1,3,4-thiadiazolyl)-9-aminoacridine (AC4) were characterized by FT-IR, ¹H NMR, mass-spectral, and elemental analysis. Amine-imine tautomerism was suggested by density functional theory (DFT) calculations. The optimized structures were obtained using B3LYP/6–311++G(d,p) level of theory. The UV–Vis absorption spectra were measured in various organic solvents. The synthesized compounds AC1–AC4 exhibit absorption spectra characteristic of typical donor–acceptor compounds. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) analysis have been used to explain the internal charge transfer (ICT) phenomena within the molecules. Also, simulated UV spectra were calculated using TD-DFT (B3LYP/6–311++G(d,p) and the results were compared with the experimental values.     

Docking-Based 3D-QSAR Studies for 1,3,4-oxadiazol-2-one Derivatives as FAAH Inhibitors

This work aimed to construct 3D-QSAR CoMFA and CoMSIA models for a series of 31 FAAH inhibitors, containing the 1,3,4-oxadiazol-2-one moiety. The obtained models were characterized by good statistical parameters: CoMFA Q² = 0.61, R² = 0.98; CoMSIA Q² = 0.64, R² = 0.93. The CoMFA model field contributions were 54.1% and 45.9% for steric and electrostatic fields, respectively. In the CoMSIA model, electrostatic, steric, hydrogen bond donor, and hydrogen acceptor properties were equal to 34.6%, 23.9%, 23.4%, and 18.0%, respectively. These models were validated by applying the leave-one-out technique, the seven-element test set (CoMFA r²_test-set = 0.91; CoMSIA r²_test-set = 0.91), a progressive scrambling test, and external validation criteria developed by Golbraikh and Tropsha (CoMFA r²₀ = 0.98, k = 0.95; CoMSIA r²₀ = 0.98, k = 0.89). As the statistical significance of the obtained model was confirmed, the results of the CoMFA and CoMSIA field calculation were mapped onto the enzyme binding site. It gave us the opportunity to discuss the structure–activity relationship based on the ligand–enzyme interactions. In particular, examination of the electrostatic properties of the established CoMFA model revealed fields that correspond to the regions where electropositive substituents are not desired, e.g., in the neighborhood of the 1,3,4-oxadiazol-2-one moiety. This highlights the importance of heterocycle, a highly electronegative moiety in this area of each ligand. Examination of hydrogen bond donor and acceptor properties contour maps revealed several spots where the implementation of another hydrogen-bond-donating moiety will positively impact molecules’ binding affinity, e.g., in the neighborhood of the 1,3,4-oxadiazol-2-one ring. On the other hand, there is a large isopleth that refers to the favorable H-bond properties close to the terminal phenoxy group of a ligand, which means that, generally speaking, H-bond acceptors are desired in this area.