窄能隙共轭聚合物:聚[(3-烷基)噻吩-2,5]-取代苯甲烯衍生物的合成与表征

Synthesis and Characterization of Narrow Bandgap Conjugated Polymer: Poly[(3-alkylthiophene-2,5-diyl)][(p-substituted) benzylidenequinomethane-2,5-diyl]s

合成了 3 -丁基噻吩和 3 -辛基噻吩 ,并分别与对硝基苯甲醛和对二甲氨基苯甲醛进行聚合反应得到了具有极低能隙的聚 ( 3 -丁基噻吩 )对硝基苯甲烯 ( PBTNBQ)、聚 ( 3 -丁基噻吩 )对二甲氨基苯甲烯( PBTDMABQ)和聚 ( 3 -辛基噻吩 )对二甲氨基苯甲烯 ( POTDMABQ) .采用红外光谱、核磁共振氢谱和紫外 -可见吸收光谱确认了产物的结构 ,发现中间产物聚 ( 3 -烷基 )噻吩取代苯甲烷衍生物中存在部分醌化产物 .根据 Eg 与入射光子能量 hν的关系 ,采用 2种模型计算了 3种聚合物薄膜的光学禁带宽度为 PBTNBQ1 .63 ,1 .84e V;PBTDMABQ1 .44,1 .75 e V和 POTDMABQ1 .3 2 ,1 .69e V,属窄能隙共轭聚合物 .

Poly[(thiophene)methene]s are the conjugated polymer with very narrow bandgap. Three poly[(3-alkylthiophene)methane]s: poly[(3-butylthiophene-2,5-diyl)][(p-nitro)benzylidenequinomethane-2,5-diyl](PBTNBQ), poly[(3-butylthiophene-2,5-diyl)][(p-N,N-dimethyl-amino)benzylidenequinomethane-2,5-diyl](PBTDMABQ) and poly[(3-octylthiophene-2,5-diyl)][( p-N,N-dimethylamino)benzylidenequinomethane-2,5-diyl](POTDMABQ) are synthesized through three steps. The products are then characterized by IR spectrum, UV-Vis absorption spectrum and 1H NMR. The results indicate that there is a part quino-structure in poly[(3-alkylthiophene-2,5-diyl)benzylidene](PATB). The absorption peak at 1 653 cm -1 in IR spectrum, the enlarged absorption of 450-600 nm in UV-Vis absorption spectrum imply that the quino-structure is really formed in this three conjugated polymers. According to the function of E g and hν, the bandgaps of these three polymers are calculated by two models which show the E g as 1.63 and 1.84 eV for PBTNBQ, 1.44 and 1.75 eV for PBTDMABQ, 1.32 and 1.69 eV for POTDMABQ, respectively.