In this paper, π-conjugated copolymers, namely N-hexylphenothiazine/cyanopyridine/phenyl/benzothiadiazole, N-hexylphenothiazine/cyanopyridine/phenyl/9,9-dihexylfluorene, and N-hexylphenothiazine/cyanopyridine/phenyl/9,9-diethylhexylfluorene were readily synthesized via Pd-catalyzed Suzuki cross-coupling reaction. The polymer structures and their photophysical properties were characterized by elemental analysis, ¹H NMR, GPC, TGA, XRD, UV-vis absorption and PL spectroscopy measurements. The coupling agent effect on photophysical properties of copolymers was investigated to rationally design polymers with particular physical properties to be employed in optoelectronic devices. The UV-vis absorption spectroscopy of copolymers showed λ_max at a range of ∼334–474 nm and red-shifted in their films to a range of ∼342–381 nm. These copolymers displayed highly intense fluorescence in their solutions and films. The PL spectra of copolymers indicated red and near-infrared light, rendering them a prospect for being red and near-infrared light-emitting materials for PLEDs. XRD analysis demonstrated a d-spacing range of ∼3.79–4.32 Å, reflecting π-π stacking and some degree of crystallinity in some polymers, and only P1 and P2 showed peaks in the small-angle region, indicating lamellar structures. To understand the relationship between molecular structures of target materials and their photophysical and photovoltaic properties, density functional theory (DFT) and its time-dependent form (TD-DFT) were employed.

在本文中，π-共轭共聚物，即N-己基吩噻嗪/氰基吡啶/苯基/苯并噻二唑，N-己基吩噻嗪/氰基吡啶/苯基/ 9,9-二己基芴和N-己基吩噻嗪/氰基吡啶/苯基/ 9,9-二乙基己基芴很容易得到。合成通过Pd催化的Suzuki交叉偶联反应。聚合物的结构及其光物理性质通过元素分析表征，¹1 H NMR，GPC，TGA，XRD，UV-vis吸收和PL光谱测量。研究了偶联剂对共聚物光物理性能的影响，以合理设计具有特定物理性能的聚合物，以用于光电器件。共聚物的紫外可见吸收光谱显示_λmax在约334-474 nm范围内，并且其薄膜的红移范围为约342-381 nm。这些共聚物在其溶液和薄膜中显示出高度强烈的荧光。共聚物的PL光谱显示红色和近红外光，使其成为PLED的红色和近红外发光材料。XRD分析显示d间距约为3.79–4.32Å，反映了某些聚合物中的π-π堆积和一定程度的结晶度，只有P1P1和P2在小角度区域显示峰，表明层状结构。为了理解靶材料的分子结构与其光物理和光伏特性之间的关系，采用了密度泛函理论（DFT）及其时变形式（TD-DFT）。