2-(ω-联苯基多亚甲基)-5-联苯基-1,3,4-(口恶)二唑的荧光光谱研究

本文测定了双荧光团化合物2-(ω-联苯基多亚甲基)-5-联苯基-1,3,4-噁二唑及其模型化合物2-甲基-5-联苯基-1,3,4-噁二唑和2,5-二联苯基-1,3,4-噁二唑的荧光光谱.对分子内、分子间激基缔合物和激基复合物的形成进行了研究,并对分子构型与形成分子内激基复合物之间关系作了初步探讨.从实验结果得到,亚甲基桥链的碳数为奇数时容易形成分子内激基复合物.     

2-(ω-联苯基多亚甲基)-5-联苯基-1,3,4-二唑的荧光光谱研究

本文测定了双荧光团化合物2-(ω-联苯基多亚甲基)-5-联苯基-1,3,4-二唑及其模型化合物2-甲基-5-联苯基-1,3,4-二唑和2,5-二联苯基-1,3,4-二唑的荧光光谱.对分子内,分子间激基缔合物和激基复合物的形成进行了研究,并对分子构型与形成分子内激基复合物之间关系作了初步探讨.从实验结果得到,亚甲基桥链的碳数为奇数时容易形成分子内激基复合物.     

激基缔合物和激基复合物的形成及溶剂效应的研究

测试了ω-对联苯基多亚甲基羧酸4-[5′-对联苯基-1,3,4-(口恶)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-,(口恶)二唑在不同极性溶剂中的荧光发射光谱。它们既能形成分子间的激基缔合物又能形成分子内的激基复合物和三分子激基复合物。实验结果表明,溶剂极性的增加,有利于分子内激基复合物和三分子激基复合物的形成。     

2-(ω-联苯基多亚甲基)-5-联苯基噁唑-1,3和2-(ω-联苯基多亚甲基)-5-联苯基噁二唑-1,3,4的合成

继2,6-二取代苯并二噁唑、2,5-二取代噁唑和2,5-二取代噁二唑及1,4-二(苯并噁唑-1,3基-2)苯等系列化合物合成及光性能研究后,又合成了双荧光发色团化合物2-(ω-联苯基多亚甲基)-5-联苯基噁唑-1,3和2-(ω-联苯基多亚甲基)-5-联苯基噁二唑-1,3,4共七种化合物。     

卟啉-噁二唑二元体系光诱导能量及电子传递研究

以5-对氨基苯基-10,15,20-三苯基卟啉及2-苯基-5-(对氨基苯基)-1,3,4-噁二唑为原料合成了系列卟啉-噁二唑二元化合物, 其结构通过¹H NMR, ESI-MS, IR, UV-Vis确定. 对合成化合物进行光谱性能测定, 结果表明, 在卟啉与噁二唑混合体系中, 存在着卟啉激发态分子向噁二唑基态分子的分子间电子传递过程, 导致卟啉激发态的荧光猝灭; 在卟啉-噁二唑二元体系中, 315 nm激发下发生了由激发态噁二唑基团至卟啉基团的能量传递, 导致噁二唑基团荧光猝灭, 卟啉基团荧光增强. 420 nm激发下不存在分子内卟啉基团向噁二唑基团的电子回传竞争; 电化学性能测定进一步表明从噁二唑基团向卟啉基团的电子传递是可能的. 因此卟啉-噁二唑二元化合物可能作为一种模型, 模拟光合作用中电子给体至叶绿素之间的电子传递过程.     

2-(2-巯苯基)苯并噁唑分子内质子转移取代基电子效应的密度泛函理论研究

在B3LYP/6-31G(d,p)和TDB3LYP/6-31++G(d,p)//CIS/6-31G(d,p)水平上研究了2-(2-巯苯基)苯并噁唑及其衍生物基态和激发态分子内质子转移现象,并探讨取代基电子效应对分子内质子转移的影响,研究结果表明,在基态时,硫醇式异构体为优势构象,供电子取代基使基态分子内正向质子转移能垒(烯醇式→酮式)升高;而吸电子取代基则可降低能垒,有利于基态分子内质子转移并有助于硫酮式异构体的稳定.在激发态时,硫酮式结构为优势构象,所研究的2-(2-巯苯基)苯并噁唑化合物及衍生物均可以发生无能垒或低能垒(≤1.5kJ/mol)的激发态分子内质子转移.巯苯基部分是激发态失活的主要活性部分,供电子基团有利于激发态的质子转移,吸电子基团使激发态跃迁困难,不利于激发态的质子转移.     

2,5-二[4-(2-芳基乙烯基)苯基]噁二唑的合成及发光特征

二乙烯联苯及其衍生物是一种可发射蓝光的小分子空穴型有机发光材料, 通过Wittig-Horner反应, 将电子传输型噁二唑环“嵌入”其中, 设计合成了6个2,5-二[4-(2-芳基乙烯基)苯基]-1,3,4-噁二唑化合物. 经光谱分析和元素分析等方法确认了它们的化学结构. IR和UV-vis分析数据表明标题化合物分子结构中的C＝C双键均为反式结构特征. 研究结果表明: 2,5-二[4-(2-对二甲氨基苯基乙烯基)苯基]-1,3,4-噁二唑具有良好的蓝色发光性能; 取代基对标题化合物的UV-vis吸收光谱和发光特性的影响显着.     

新型1,3,4-噁二唑衍生物的合成与性质研究

研制高效载流子传输材料是提高有机电致发光器件性能的关键. 采用对酯对二酰氯(5)与含不同链长烷氧取代基的苯甲酰肼(2)缩合制备了一系列腰接羧基1,3,4-噁二唑衍生物, 即1,4-二[5-(4-烷氧基苯)-1,3,4-噁二唑基]-2,5-二羧基苯(7; 烷氧基＝OCnH2n＋1; n＝8, 12, 16), 并采用UV-vis吸收和荧光光谱对合成物进行了表征. 结果表明: 7的分子结构中羧基的横向引入, 对化合物的光物理性质和能带结构产生较大影响. 这些噁二唑化合物的LUMO及HOMO值分别介于－3.62与－3.58 eV之间及－6.94与－6.90 eV之间, 说明它们可能具有良好的电子传输性.     

含1,3,4-噁二唑环PPV齐聚物的合成及发光特性研究

含有1,3,4-噁二唑结构单元的PPV齐聚物是一类具有良好电子传输功能的发光材料。通过Wittig—Homer反应合成了2,5-二{4-[2-(取代苯基)乙烯基]苯基}-1,3,4-噁二唑(1)。1的化学结构经元素分析和光谱分析确认,其分析数据表明1分子结构中的C=C双键均为反式结构。苯环上的取代基对1的UV—Vis吸收光谱和PL荧光光谱有显著影响。     

1,3,4-噁二唑三氮烯衍生物的合成及生物活性测定

利用拼合原理,将具有生物活性的三氮烯结构与1,3,4-噁二唑结构相拼合,设计合成了11个未见报道的1,3,4-噁二唑三氮烯衍生物.所合成化合物经1H NMR,IR和HRMS得到表征.用四甲基偶氮唑盐(MTT)法法评价了该类化合物对胃癌细胞(MGC803)和前列腺癌细胞(PC-3)的抑制作用,结果显示化合物2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(4-甲氧基苯基)-1,3,4-噁二唑(b4)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(2-甲氧基苯基)-1,3,4-噁二唑(b9)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(3,4-甲叉二氧基苯基)-1,3,4-噁二唑(b10)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(吡啶-4-基)-1,3,4-噁二唑(b11)对前列腺癌细胞的抑制作用强于典型三氮烯药物达卡巴嗪(DTIC),其IC50值分别为74.145,87.790,87.327和104.875μmol/L,而对胃癌细胞则几乎没有抑制作用.采用微量肉汤稀释法测试了该类化合物对大肠埃希菌(E.coli.)和金黄葡萄球菌(S.aureus)的抑制作用,结果显示这类化合物对这两种细菌并没有表现出抑制作用.     

Synthesis and characterization of 1,3,4-oxadiazole derivatives containing alkoxy chains with different lengths

The synthesis, optical properties, electrochemical properties, electronic structures and applications in electroluminescent device of three series of 1,3,4-oxadiazole derivatives, 1,4-bis[(4-methylphenyl)-1,3,4-oxadiazolyl]phenylene (OXD₁), 5,5′-di-(4-methyl)-2,2′-p-(2,5-bisalkoxyphenylene)-bis-1,3,4-oxadiazole (OXD_2–n) and 1,4-bis[(4-alkoxyphenyl)-1,3,4-oxadiazolyl]phenylene (OXD_3–n) are reported. The molecular structures of the oxadiazole compounds were confirmed by FT-IR, ¹H NMR spectroscopy and elemental analysis. The optical and electrochemical properties of the compounds were investigated by UV–vis absorption and photoluminescence spectroscopy as well as cyclic voltammetry. The results show that introduction of two alkoxy groups whose electron-donating ability is stronger than that of methyl groups increases the electron density of the conjugated segment of OXD_2–n (with side-on alkoxy substituents) and OXD_3–n (with end-on alkoxy substituents), and thus leads to the absorption maximum bathochromic-shift compared to that of OXD₁. The HOMO and LUMO energy levels of the compounds studied are in the range of −2.78 to −2.89 and −5.75 to −6.20 eV. Calculations on the representative compounds by the Dmol³ package of MS Modeling 3.0 revealed that the increase of energy levels in both OXD_2–n and OXD_3–n was due to the change of the frontier molecular orbital distribution in the central benzene ring. The light-emitting devices have been fabricated using blends of MEH-PPV and these compounds as emissive layers, among which, maximum brightness up to 11810 cd m⁻² (8.5 V) has been observed, which is 40 times brighter than that with MEH-PPV. The result of the devices suggested that oxadiazole derivatives studied function well as electron-transporting materials and can be used in LEDs, and thus to enhance the efficiency of LEDs.     

High-efficiency poly(p-phenylenevinylene)-based copolymers containing an oxadiazole pendant group for light-emitting diodes

A new series of high brightness and luminance efficient poly(p-phenylenevinylene) (PPV)-based electroluminescent (EL) polymers, poly[2-[4-[5-(4-(3,7-dimethyloctyloxy)phenyl)-1,3,4-oxadiazole-2-yl]phenyloxy]-1,4-phenylenevinylene] (Oxa-PPV), poly[2-[2-((3,7-dimethyloctyl)oxy)phenoxy]-1,4-phenylenevinylene] (DMOP-PPV), and their corresponding random copolymers, poly[[2-[4-[5-(4-(3,7-dimethyloctyloxy)phenyl)-1,3,4-oxadiazole-2-yl]phenyloxy]-1,4-phenylenevinylene]-co-[2-[2-((3,7-dimethyloctyl)oxy) phenoxy]-1,4-phenylenevinylene]] (Oxa-PPV-co-DMOP-PPV), with an electron-deficient 1,3,4-oxadiazole unit on the side groups, were synthesized through the Gilch polymerization method. The newly designed and synthesized asymmetric molecular structures of Oxa-PPV, DMOP-PPV, and Oxa-PPV-co-DMOP-PPV were completely soluble in common organic solvents, and defect-free optical thin film was easily spin-coated onto the indium tin oxide (ITO) substrate. Oxa-PPV shows a high glass transition temperature (T(g)), which might be an advantage for long time operation of polymer light-emitting diodes (PLEDs). Double-layer LEDs with an ITO/PEDOT/polymer/Al configuration were fabricated by using those polymers. Electrooptical properties and device performance could be adjusted by introducing the Oxa-PPV content in the copolymers. The emission colors could be tuned from green to yellowish-orange via intramolecular energy transfer. The improved device performance of Oxa-PPV over DMOP-PPV and Oxa-PPV-co-DMOP-PPV may be due to better electron injection and charge balance between holes and electrons and also efficient intramolecular energy transfer from 1,3,4-oxadiazole units to PPV backbones. The maximum brightness and the luminance efficiency of Oxa-PPV were up to 19395 cd/m(2) at 14 V and 21.1 cd/A at 5930 cd/m(2). The maximum luminance efficiency of Oxa-PPV is ranked the highest value among the PPV derivatives to date.     

以N为耦合中心多枝分子的双光子上转换荧光

采用非线性透过率法研究了以N为耦合中心的多枝化合物N-[4-{2-(3,5-二-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2-]苯基}-1-乙烯基}苯基}-N,N-二苯胺(BPODPA), N,N-双[4-{2-(3,5-二-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2-]苯基}-1-乙烯基}苯基}-N-苯胺(BBPOPA)和N,N,N-三[4-{2-(3,5-二-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯基}-1-乙烯基}苯基}胺(TBPOA)的双光子吸收性质, 测定了化合物的单光子荧光光谱和双光子上转换荧光光谱, 研究了多枝化对三苯胺分子双光子吸收和双光子激发荧光性质的影响.在800 nm波长的激光激发下,化合物BPODPA、BBPOPA和TBPOA在二氯甲烷溶液中发出很强的蓝绿色双光子上转换荧光, 荧光峰分别位于502、515 和518 nm. 这些多枝结构化合物的双光子吸收截面较大, 双光子吸收增强来源于多枝分子中扩展的π共轭体系和重复单元的协同效应.     

Research on the fluorescence spectra of 2-(ω-biphenylylpolymethylene)-5-biphenylyl-1,3,4-oxadiazole

The fluorescence spectra of bichromophore compounds 2-(ω-biphenylylpolymethylene)-5-biphenylyl-1,3,4-oxadiazole ( 1—4 ) and its corresponding model compounds 2-methyl-5-biphenylyl-1,3,4-oxadiazole ( 5 ) and 2,5-dibiphenylyl-1,3,4-oxadiazole ( 6 ) have been determined. The formation of intra- and intermolecular excimers and exciplexes have been studied. The relationship between the molecular configuration and the formation of intra exciplex have been discussed. From the experimental results, it can be seen that when the number of the carbon atoms of the methylene bridge is odd, intra exciplex is readily formed.     

Photophysical processes of a fluorene derivative containing 1,3,4-oxadiazole

The photophysical processes of 9,9-bis[4'-[2'-phenyl-5'-(3'-(methacryl-amido)phenyl)]-1',3',4'-oxadiazolylphenyl]fluorene (F-MAOP) formed by Heck reaction of 9,9-bis(4'-iodophenyl)fluorene (F-IP) and 2-phenyl-5-[3'-(methacrylamido)phenyl]-1,3,4-oxadiazole (OXD) have been carefully studied. The results show that the compound emits blue and blue-violet light and the emission spectra exhibit obvious solvent effect. With the increase of polarity of solvents, the fluorescence spectra change obviously and appear blue shift at room temperature. In addition, the light-emitting can be quenched by both electron donor (N,N-dimethylaniline, DMA) and electron acceptor (C60). When N,N-dimethylaniline is gradually added into the solution of F-MAOP, the emission intensities of fluorescence are unusually increased. But when the concentration of DMA beyond a certain scope, the emission intensities of fluorescence are gradually decreased. The dimolecular exciplex between F-MAOP and C60 are formed and the quenching effect follows the Stern-Volmer equation. Moreover, interaction between F-MAOP and carbon nanotubes (CNTs) is also studied by fluorescent quenching.     

侧链接有噁二唑的硅氧烷嵌段聚对苯乙烯撑衍生物的合成及其性能研究

在强碱条件下,单体2-(4-辛氧基苯基)-5-[4-(2,5-二溴甲基苯氧基)苯基]-1,3,4-噁二唑和二甲基二对溴甲基苯氧基硅烷发生Gilch脱卤聚合反应,成功合成了一种新型的侧链接有噁二唑的硅氧烷嵌段聚对苯乙烯撑衍生物(8),其结构经FT-IR表征。用UV-Vis,FL和DSC研究了8的光学性能和热稳定性。结果表明,8的热稳定性较单体有所改善;最大发射峰在480 nm。     

Synthesis of redox-active, intramolecular charge-transfer chromophores by the [2+2] cycloaddition of ethynylated 2H-cyclohepta[b]furan-2-ones with tetracyanoethylene

Ethynylated 2H-cyclohepta[b]furan-2-ones 5-15 have been prepared by Pd-catalyzed alkynylation of 3-iodo-5-isopropyl-2H-cyclohepta[b]furan-2-one (2) with the corresponding ethynylarenes or the reaction of 2-iodothiophene with 3-ethynyl-5-isopropyl-2H-cyclohepta[b]furan-2-one (4) under Sonogashira-Hagihara conditions. Compounds 5-15 reacted with tetracyanoethylene in a formal [2+2] cycloaddition reaction, followed by ring opening of the initially formed [2+2] cycloadducts, cyclobutenes, to afford the corresponding 1,1,4,4-tetracyanobutadienyl (TCBD) chromophores 16-26 in excellent yields. The intramolecular charge-transfer interactions between the 2H-cyclohepta[b]furan-2-one ring and TCBD acceptor moiety were investigated by UV/Vis spectroscopy and theoretical calculations. The redox behavior of the novel TCBD derivatives 16-26 was examined by cyclic voltammetry and differential pulse voltammetry, which revealed multistep electrochemical reduction properties, depending on the number of TCBD units in the molecule. Moreover, a significant color change was observed by UV/Vis spectroscopy under electrochemical reduction conditions.     

2,4和8-支噁二唑衍生物的三光子吸收和三光子上转换荧光

用飞秒Ti:sapphire激光测定了3个对称噁二唑衍生物4-{N,N-双[4-(4-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯乙烯基)苯基]氨基}苯甲醛(Bis-oxa)、2,5-双{4-[2-N,N-双(4-{4-[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯乙烯基}苯基)氨基苯乙烯基]苯基}-1,3,4-噁二唑(Quadri-oxa)和2,5-双(4-{2-N,N-双[({3,5-二[5-(4-叔丁基苯基)-1,3,4-噁二唑-2]苯基}乙烯基)苯基]氨基苯乙烯基}苯基)-1,3,4-噁二唑(Octu-oxa)的三光子吸收谱和三光子荧光光谱. 在1260 nm飞秒激光激发下, 2,4和8-支噁二唑衍生物的三光子吸收系数分别为5.0×10^-5, 10.0×10^-5和10.0×10^-5 cm³/GW², 三光子频率上转换荧光发射波长分别为533, 544和551 nm. 研究了多支化合物线性吸收和透过、单光子荧光及量子产率、荧光寿命、多光子荧光光谱和三光子吸收系数谱. 对称多支噁二唑衍生物具有很强的三光子吸收和上转换荧光性质.