Synthesis, Structure and Photophysical Properties of Silole-Oxadiazole Copolymers

• Published in: Chinese journal of chemistry Vol. 31; no. 6; pp. 779 - 786
• Main Authors: Zhang, Tingting, Zhu, Chaoqiang, Ma, Yuwen, Wang, Chengyun, Shen, Yongjia
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.06.2013; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: 2,5‐bis(4‐ethynylphenyl)‐1,3,4‐oxadiazole; 2,5‐bis(5‐bromo‐2‐thienyl)silole; 4-oxadiazole; 5-bis(4-ethynylphenyl)-1; 5-bis(5-bromo-2-thienyl)silole; Chemistry; Chemistry, Multidisciplinary; conjugated polymer; LUMO能级; Physical Sciences; Science & Technology; Sonogashira reaction; Suzuki; Suzuki reaction; 光物理性质; 共聚物; 化学结构; 反应合成; 循环伏安法; 恶二唑; EXPLOSIVES; MOLECULAR-WEIGHT; 5-bis(4-ethynylphenyl)-1; BLENDS; MISCIBILITY; TRANSITION; 2; 3; POLYMER; 4-oxadiazole; AGGREGATION-ENHANCED EMISSION; 5-bis(5-bromo-2-thienyl)silole; BEARING; Sonogashira reaction; conjugated polymer; DERIVATIVES; FLUORENE; Suzuki reaction
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.201300121

A new conjugated copolymer （PTST-DyOXD） derived from 1,1-dimethyl-3,4-diphenyl-2,5-bis（5-bromo-2- thienyl）-silole （TST） and 2,5-bis（4-ethynylphenyl）-l,3,4-oxadiazole （DyOXD） was synthesized by Pd（0）-catalyzed Sonogashira coupling reaction. For comparison, another copolymer without acetenyl group （PTST-OXD） was also synthesized by Pd（0）-catalyzed Suzuki coupling reaction. Chemical structures and optoelectronic properties of the copolymers were characterized by IH NMR, 13C NMR, IR, UV-vis absorption, photoluminescence and cyclic voltammetry. The number-average molecular weight （Mn） is 4010 Da for PTST-DyOXD and 3890 Da for PTST-OXD, respectively. The thermogravimetric analysis （TGA） measurements show that they have good thermal stability with decomposition temperature at 312 and 318 ~C, respectively. The optical band gap is 2.21 eV for PTST-DyOXD and 2.10 eV for PTST-OXD based on the absorption onset. CV analysis revealed the LUMO level of PTST-DyOXD is -3.04 eV, lower than that of PTST-OXD （about -2.89 eV）, which is attributed to the introduction of acetylene group in PTST-DyOXD, increasing the system of the conjugate chain length.