Oxidative polymerization of N-substituted carbazoles

Poly(N-vinylcarbazole), poly(N-carbazole) and poly(N-ethylcarbazole) powders were chemically synthesized by the reaction of ceric ammonium nitrate (CAN) with N-vinylcarbazole carbazole and N-ethylcarbazole in acetonitrile. Products were characterized by elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and viscosity, X-ray fluorescence and four-probe conductivity measurement. It is found that when a suitable concentration of CAN is used in the polymerization process, the conductivity of chemically synthesized polymers can be improved further by controlling the CAN addition. © 1997 John Wiley & Sons, Ltd.     

主链含N-烷基咔唑环结构聚芳醚酮的性能表征

对含N-烷基咔唑环结构的聚芳醚酮(PPCzE、PPCzB和PPCzH)进行基本物理性能方面的表征,并与商业化酚酞基聚芳醚酮(PEK-C)进行比较。 咔唑环结构的引入使聚合物在345 nm附近有强紫外光吸收并表现出发蓝光能力。 由于疏水性烷基侧链的存在,聚合物薄膜的水接触角(87°~103°)大于PEK-C(76°),但同时烷基侧链所引起的聚合物链间距的增大导致聚合物的吸水率(0.65%~0.86%)高于PEK-C(0.56%)。 此外,聚合物表现出较好的尺寸稳定性(平均线膨胀系数6.4×10^-5 ℃^-1)和电绝缘性能(体积电阻率10¹⁶ Ω·cm)。 聚合物的拉伸模量在1.9~2.0 GPa之间,拉伸强度在72.5~75.0 MPa之间以及断裂伸长率在6.5%~7.2%之间。 高温条件下(≤225 ℃),PPCzE仍具有良好的拉伸性能。     

含咔唑生色团的聚磷腈的合成与表征

通过后重氮偶合方法制备了一种含咔唑双功能生色团的聚磷腈光折变高分子,并用1H-NMR3、1P-NMRI、R、UV-vis、GPC以及DSC、TG等测试手段对聚合物进行了分析和表征。1H-NMR、IR、UV-vis谱图表明对硝基偶氮苯基团连接在咔唑环上。31P-NMR谱图上的单峰说明聚二氯磷腈分子链上的氯已经全部被咔唑基团取代,而且后功能化反应条件没有破坏磷腈主链结构。GPC测得聚磷腈的Mw=1.28×104。热分析结果显示聚磷腈的Tg=20℃,并在300℃开始分解。     

咔唑衍生物的固相合成及其双光子吸收和光存储应用

以N-乙基咔唑为原料,通过室温固相化学反应改进合成了2种双光子吸收材料(咔唑类衍生物2, 8-二[2'-(吡啶-4"-基)乙烯基]-5-乙基咔唑(L1),2, 8-二[2'-(吡啶-2"-基)乙烯基]-5-乙基咔唑(L2),其结构经¹H NMR,IR和MS确证,利用Z-扫描技术,测试了其纳秒下的双光子吸收截面为6 210和5 590 GM (1 GM = 1 ´ 10 ^-50 cm ⁴ · s · photon ^-1),用820 nm的飞秒单脉冲激光作为写入激光对存储介质进行双光子光漂白,对其作为三维光存储材料作了初步的探索。     

新型咔唑衍生物的合成及其晶体结构

通过9-乙基咔唑-3-甲醛与4-氨基-3,5-二甲基-1,2,4-三氮唑反应,合成了一种新型咔唑衍生物-- 9-乙基咔唑-3-甲醛缩4-氨基-3,5-二乙基-1,2,4-三氮唑(1),其结构经1H NMR, IR和X-射线单晶衍射表征.1属单斜晶系,P2(1)/n空间群,晶胞参数为:a=8.829(8)(A), b=9.863(10)(A), c=19.530(15)(A), β=101.65(5)°, V=1 666(3)(A)3, Dc=1.266 g·cm-3, Z=4, F(000)=672, μ=0.079 mm-1.最终偏离因子R1=0.075 6.     

Synthesis and structures of two novel indolo[3,2-b] carbazole derivatives

Indolocarbazole derivatives have already been reported to be good organic semiconductor candidates. The knowledge of the relationship between the structure and packing of molecules in crystal is indispensable in design of high performance organic semiconductor materials. Two new indolocarbazole derivatives, 2,8-dibromo-5,11-di-[4-(isoindole-1,3-dione-2-yl)butyl]indolo[3,2-b]carbazole (I) and 2,8,6,12-tetrabromo-5,11-di-(4-chlorobutyl)indolo[3,2-b]carbazole (II) have been synthesized and the crystal structures have been studied. The dichloromethane solvate of (I), C₄₂H₃₂Br₂N₄O₄ · 2CH₂Cl₂, is monoclinic, space groups P2₁/n. Unit cell parameters are a = 11.6847(2), b = 12.6942(2), c = 13.7899(2) Å, β = 91.8220(10)°. Unlike other indolo[3,2-b]carbazole derivatives, there is no any π–π stacking between the indolocarbazole backbone of two adjacent molecules in the crystal. Since the isoindole-1,3-dione-2-yl is introduced in 5- and 11-positions in the molecule, the intermolecular short contacts mainly localize in between the pendant groups of the neighboring indolocarbazole molecules. The compound (II) is also monoclinic with P2₁/c space groups. Unit cell parameters are a = 4.6427(9), b = 11.425(2), c = 24.511(4) Å, β = 93.47(1)°. In contrast with compound (I), the molecules of (II) possess strong face-to-face π–π stacking. The crystal structures were studied in detail. It is concluded that linear pedant groups benefit to co-facial π–π interaction. Additionally, the molecule electronic spectra were studied by quantum chemistry theoretical calculation.     

4,7-二(2-溴代噻吩-5-基)-2,1,3-苯并噻二唑-N-(1-辛基壬烷基)咔唑在ZnS(100)表面吸附的理论研究

采用密度泛函理论中的广义梯度近似(DFT/GGA)方法, 在PW91/DNP水平上研究了4,7-二(2-溴代噻吩-5-基)-2,1,3-苯并噻二唑-N-(1-辛基壬烷基)咔唑(简称PC-DTBT)的低聚合物(PC-DTBT)n(n=1-5)的稳定性和化学活性. 结果表明: 随着聚合度增加, (PC-DTBT)n的稳定性降低, 化学活性增强. 采用密度泛函理论与周期性平板模型相结合的方法, 研究了PC-DTBT单体在ZnS(100)表面的吸附, 通过吸附前后化合物PC-DTBT的Mulliken charge和前线轨道分析表明: 当PC-DTBT吸附在ZnS (100)表面时, ZnS(100)表面向PC-DTBT转移0.200 e电荷, 前线轨道能隙变窄. 理论预测的结果与实验值吻合.     

Theoretical studies of the structural,electronic and optical properties of carbazole‐based compounds

Carbazole derivatives have drawn increasing attention recently in organic electronic device applications because of their particular optoelectronic properties. An in‐depth theoretical investigation was elaborated in this paper to reveal the molecular structures, optoelectronic properties, and the structure‐property relationships of different carbazole‐linked functional groups. The geometric and electronic structures in ground and the mobility for the hole and electron are both calculated by density functional theory method. The excited‐state geometries of these compounds were obtained through Single‐excitation Configuration Interaction method, and time‐dependent density functional theory calculation results described the absorption and emission spectra properties, respectively. Some conclusions are as follows: (1) enlarging the π‐conjugated area, the corresponding spectra red shifted markedly; (2) by introducing the electron‐donor such as carbazole, the spectra blue shifted slightly; (3) compared with compound 1, the spectra for these compounds are hardly influenced by introducing an electron‐acceptor or heterocyclic substitution. On all accounts, these compounds are interesting optoelectronic functional materials. On the basis of their structural modifiability, the arylamine derivatives substituted carbazole compounds have great potential in the applications of organic light‐emitting diodes, organic solar cells, and sensors. Copyright © 2011 John Wiley & Sons, Ltd.     

Three‐photon absorption properties of a novel symmetrical Carbazole derivative having terminal 1,10‐phenanthroline rings via carbon–nitrogen (C = N) double bond

Three‐photon absorption (3PA) properties of symmetric‐type carbazole derivatives show great potential for application in light‐activated therapy and optical limiting. A novel symmetrical carbazole derivative (abbreviated as POCP) with end‐groups of 1,10‐phenanthroline rings as the donor moieties, chained via carbon–nitrogen (C = N) double bond, has been synthetized and its three photon absorption properties has been also determined by using a Q‐switched Nd: YAG laser pumped with 30 ps pulses at 1064 nm in dimethylformamide. The measurement of 3PA cross‐section of this compound is performed by open aperture Z‐scan and σ_3PA is 481 × 10^–78 cm⁶ ? s²/photon² for the transition S₀ → S₁. The influence of the molecular structure of this compound on three‐photon absorption cross‐sections is discussed micromechanically by Austin model 1 and Zerner's Intermediate Neglect of Differential Overlap/S method. Copyright © 2012 John Wiley & Sons, Ltd.     

Bis(4-diphenylaminophenyl)carbazole end-capped fluorene as solution-processed deep-blue light-emitting and hole-transporting materials for electroluminescent devices

A new highly fluorescent bis(4-diphenylaminophenyl)carbazole end-capped fluorene (TCF) is synthesized and characterized. TCF is an amorphous molecular glass with a high glass transition temperature of 169 °C, is electrochemically stable, and gives strong blue emission both in solution and solid state. It showed greater ability as a solution processed blue emitter and hole-transporter for OLEDs than commonly used NPB. High-efficiency, deep-blue and Alq3-based green devices with luminance efficiencies and CIE coordinates of 0.93 cd/A and (0.16, 0.09), and 3.78 cd/A and (0.29, 0.45) were achieved, respectively.