Synthesis and characterization of 1,3,4,6-tetraarylpyrrolo[3,2-b]-pyrrole-2,5-dione (isoDPP)-based donor–acceptor polymers with low band gap
Synthesis and characterization of 1,3,4,6-tetraarylpyrrolo[3,2-b]-pyrrole-2,5-dione (isoDPP)-based donor–acceptor polymers with low band gap
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DOI：
10.1039/c3py00570d
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发表时间：
2013-07
影响因子：
4.6
通讯作者：
Haichang Zhang;Irina Welterlich;J. Neudörfl;B. Tieke;Chaonan Yang;Xuegang Chen;Wenjun Yang
中科院分区：
文献类型：
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作者：
Haichang Zhang;Irina Welterlich;J. Neudörfl;B. Tieke;Chaonan Yang;Xuegang Chen;Wenjun Yang
本文报道了以四芳基二酮吡咯并[3，2-B]吡咯（isoDPP）为结构单元的新型π共轭给体-受体（D-A）聚合物的合成。在钯催化的3，6-双（2-甲氧基苯基）-1，3-二氧戊环的Stille偶联反应中制备了聚合物。（5-溴噻吩-2-基）-1，4-二苯基-吡咯并[3，2-B]吡咯-2，5-二酮（M1）与4，β 4 ′-二（2-乙基己基）-5，5 ′-双（三甲基锡）二噻吩并[3，2-B]：2′，3 ′-d]噻咯（M2）或（4，8-双-（2-乙基己氧基）苯并[1，2-B]：4，5-B]二噻吩-2，6-二基）双（三甲基锡烷）（M3）。聚合物具有1.53和1.67 eV的低带隙，最大吸收带为523 nm和620 nm，消光系数分别为6.5 × 104 L mol−1 cm−1和2.6 × 104 L mol−1 cm−1。低荧光量子产率在0.13%和0.82%之间。量子化学计算表明，具有高度离域HOMO轨道和LUMO电子在噻吩基-isoDPP单元的本地化的近平面的骨干。M1的X射线结构分析表明噻吩基和isoDPP核之间的二面角为14.1°，内酰胺苯基和isoDPP核的二面角为76.6°，后者阻止了单体的任何π-堆叠。该聚合物显示出高的玻璃化转变温度（Tg）和优异的热稳定性。光辐射研究表明，聚合物是非常稳定的紫外线和可见光在溶液中。光谱电化学研究表明，可逆的电致变色与710 nm附近的等吸光点。
The synthesis of new π-conjugated donor–acceptor (D–A) polymers containing tetraaryl-diketopyrrolo[3,2-b]-pyrrole (isoDPP) as the building block is described. Polymers were prepared upon palladium-catalyzed Stille coupling of 3,6-bis(5-bromothien-2-yl)-1,4-diphenyl-pyrrolo[3,2-b]pyrrole-2,5-dione (M1) with 4,4′-bis(2-ethylhexyl)-5,5′-bis(trimethyltin)dithieno[3,2-b:2′,3′-d]silole (M2) or (4,8-bis-(2-ethylhexyloxy)benzo[1,2-b:4,5-b]dithiophene-2,6-diyl)bis(trimethylstannane) (M3). The polymers exhibit low band gaps of 1.53 and 1.67 eV, broad absorption bands with maxima of 523 nm and 620 nm, and high extinction coefficients of 6.5 × 104 L mol−1 cm−1, and 2.6 × 104 L mol−1 cm−1, respectively. Low fluorescence quantum yields between 0.13% and 0.82% were detected. Quantum chemical calculations indicated a nearly planar backbone with highly delocalized HOMO orbitals and localization of the LUMO electrons at the thienyl-isoDPP units. The X-ray structure analysis of M1 indicated a dihedral angle of 14.1° between the thienyl groups and the isoDPP core, and a 76.6° dihedral angle of the lactam phenyl group and the isoDPP core, the latter preventing any π-stacking of the monomers. The polymers show high glass transitions (Tg) and excellent thermal stability. Photoirradiation studies indicate that the polymers are extremely stable to UV and visible light in solution. Spectroelectrochemical studies indicated a reversible electrochromism with isosbestic point near 710 nm.