Liu Siyang, Lin Pengju, Niu Fangfang, Zeng Pengju, Zhang Bin
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou 213164, China.
Materials (Basel). 2018 Apr 17;11(4):617. doi: 10.3390/ma11040617.
A series of symmetric carbazole derivatives (CzP-H, CzP-CN, CzP-Me, and CzP-OMe), which comprise electron-donating and electron-drawing groups appending on a phenyl core, was synthesized and characterized in detail. These compounds exhibit excellent thermal stabilities, with thermal decomposition temperatures exceeding 400 °C. From the fluorescent spectra in film, CzP-H, CzP-Me, and CzP-OMe showed UV to blue-violet emission, with peaks at 396 nm, 402 nm, and 392 nm, respectively. The energies of CzP-H, CzP-CN, CzP-Me, and CzP-OMe were 3.39 eV, 2.83 eV, 3.50 eV, and 3.35 eV, respectively. From the electrochemical measurements, the highest occupied molecular orbital (HOMOs) energy levels were −5.30 eV, −5.64 eV, −5.46 eV, and −5.24 eV for CzP-H, CzP-CN, CzP-Me, and CzP-OMe, respectively. Through calculations from HOMO energy levels and energies, the lowest unoccupied molecular orbital (LUMOs) energy levels of CzP-H, CzP-CN, CzP-Me, and CzP-OMe were −1.91 eV, −2.81 eV, −1.96 eV, and −1.89 eV, respectively. Therefore, the introduction of different substitutes in phenyl cores would distinctly affect the photophysical properties. These results indicate that the prepared carbazole derivatives could be potential candidates for realizing ultraviolet or blue-violet emission.
合成并详细表征了一系列对称咔唑衍生物（CzP-H、CzP-CN、CzP-Me和CzP-OMe），这些衍生物在苯基核心上连接有供电子基团和吸电子基团。这些化合物表现出优异的热稳定性，热分解温度超过400℃。从薄膜中的荧光光谱来看，CzP-H、CzP-Me和CzP-OMe呈现出紫外到蓝紫色发射，峰值分别位于396nm、402nm和392nm。CzP-H、CzP-CN、CzP-Me和CzP-OMe的能量分别为3.39eV、2.83eV、3.50eV和3.35eV。通过电化学测量，CzP-H、CzP-CN、CzP-Me和CzP-OMe的最高占据分子轨道（HOMO）能级分别为−5.30eV、−5.64eV、−5.46eV和−5.24eV。通过从HOMO能级和能量进行计算，CzP-H、CzP-CN、CzP-Me和CzP-OMe的最低未占据分子轨道（LUMO）能级分别为−1.91eV、−2.81eV、−1.96eV和−1.89eV。因此，在苯基核心中引入不同的取代基会明显影响光物理性质。这些结果表明，所制备的咔唑衍生物可能是实现紫外或蓝紫色发射的潜在候选物。
