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1.
D-A结构的9,9-二芳基芴类发光材料的合成、表征及性能 总被引:1,自引:0,他引:1
设计合成了一系列以三苯胺结构为核心的具有推电子-拉电子(D-A)结构的9,9-二芳基芴类有机小分子. 研究了介质极性对吸收与发射光谱行为的影响及分子结构与其发光能力的关系. 该类化合物荧光发射波长范围在430-530 nm. 并在特定极性溶剂中观察到双重荧光现象. 溶剂效应显示该类化合物随着介质极性的增加, 分子内电荷转移态(ICT)的荧光发射峰波长先红移后蓝移且荧光强度降低, 表现出扭曲的分子内电荷转移(TICT)行为. 该类化合物的最高占有分子轨道(HOMO)能级位于-5.24 - -5.50 eV, 且可以通过改变取代基电负性的强弱来调节. 所得化合物的玻璃化转变温度为192-206 °C, 热重分析(TGA)表明化合物的热分解温度都在400 °C以上, 具有良好的热稳定性. 相似文献
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合成了一组带不同取代基的三芳基吡唑啉化合物,对它们在不同极性溶剂中的光物理行为(如荧光量子产率,荧光寿命等)进行了测定指出:这类化合物在光的激发下除存在有分子内共轭条件下的电荷转移行为外,还存在着分子内非共轭条件下的电子转移,本工作还以三芳基吡唑啉化合物为猝灭剂对氧鎓盐的荧光猝灭能力进行了研究,并对所得结果作了讨论。 相似文献
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本工作对带有不同取代基的1,3,5-三芳基-2-吡唑啉类化合物的稳态光物理行为进行了研究,从它们在不同极性溶剂中的吸收光谱和荧光发射光谱以及荧光量子效率的结果表明,这类化合物分子内共轭的及非共轭的光诱导电荷转移的趋向取决于上述两过程间的竞争。 相似文献
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吡唑啉衍生物具有优异的空穴传输性能和光致发光性能。本文采用荧光光谱法研究了化合物1,5-二苯基-3-联苯基-2-吡唑啉(DBP)的荧光光谱行为。DBP有较强的荧光发射,其光谱行为受溶剂极性和酸度影响显著。随着溶剂极性增加,DBP的荧光发射峰明显红移,其激发态与基态的偶极矩差值增大,发生了分子内电荷转移。在强酸性条件下,DBP的荧光被显著猝灭,量子产率降低。另外,受体分子芴酮或三硝基芴酮能有效猝灭DBP的荧光,其猝灭机理为动态猝灭,两者发生了较强的分子间光诱导电荷转移。DBP与三硝基芴酮间的电荷转移作用明显大于芴酮。 相似文献
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利用Wittig反应合成了一个以萘为π-Center的对称型“D-π-D”有机绿色发光化合物1,4 双(4′-N,N-二甲基氨基苯乙烯基)萘(BDASN),并测试了其在不同环境中的光谱性质.在378nm激发波长的激发下,BDASN显示出很强的荧光发射峰,峰位在521nm(CH2Cl2).随着溶剂极性增大,最大发射波长红移且荧光强度降低,与“D-π-A”分子具有相似的分子内电荷转移(TICT)行为.在β-环糊精(β-CD)中BDASN的绿色发光带被猝灭,同时在450nm附近蓝发光带的荧光强度骤增. 相似文献
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本文设计合成了两个新的星状分子1和2,它们分别含有一个三苯胺和苯环的核,并都以三个2,4-二氰基-3-二乙氨基-9,9-二乙基芴为端基。光学性质研究表明,这两个具有D-A结构的化合物都显示出分子内电荷转移的性质。化合物1在强极性溶剂中表现出了双荧光发射特性。这两个化合物还显示出中等强度的荧光和高的热稳定性,这预示了它们在蓝色荧光材料方面的应用潜力。 相似文献
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合成了新的N-乙基咔唑衍生物: 3,6-二[2-(8-羟基喹啉基)乙烯基]咔唑(4)及其锌配合物(5); 化合物4经质谱、红外光谱、核磁共振氢谱、元素分析表征其结构, 并测定了它的荧光光谱. 结果显示: 化合物4的荧光发射为蓝绿色光(500 nm), 其发射光谱随着溶剂极性的增大荧光光谱向长波方向移动(即发生红移); 同时, 考察了化合物5的荧光性质, 其荧光发光峰值为600 nm, 与2-甲基-8-羟基喹啉锌相比, 发生了明显的红移. 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
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Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner. 相似文献