Yan Wen, Chaitanya Kadali, Sun Zhi-Dan, Ju Xue-Hai
Key Laboratory of Soft Chemistry and Functional Materials of MOE, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China.
J Mol Model. 2018 Feb 24;24(3):68. doi: 10.1007/s00894-018-3596-9.
Based on a prototype sensitizer W2, we designed triarylamine-based p-type sensitizers W2-1 to W2-7 that contain modified π-spacers (π'), a π-spacer and two anchors. For W2-1 to W2-4, instead of 2,1,3-benzothiadiazole in W2, thieno[3,4-b]-1,4-dioxin, thiophene, thieno[3,4-c][1,2,5]thiadizole, thiazolo[5,4-d]thiazole are π' and thiophene as π-spacer. For W2-5 to W2-8, π' and π are same, with 2,1,3-benzothiadiazole, thieno[3,4-b]-1,4-dioxin, thieno[3,4-c][1,2,5]thiadiazo, thiazolo[5,4-d]thiazole, respectively, as the π'-spacers. Structure optimization, electronic level and absorption characters were calculated with density functional theory (DFT) and time-dependent DFT (TDDFT) at the CAM-B3LYP/6-311G (d,p). The solvent effect was involved using a polarized continuum model in chloroform. The results showed that the highest occupied molecular orbital and the lowest unoccupied molecular orbital guarantee sufficient hole injection (lower than -0.2 eV), and dye regeneration (lower than -0.2 eV). W2-4 has higher light-harvesting efficiency (LHE) (0.994) and larger overlap with the visible light from 400 nm to 600 nm. Finally, the results suggest that the driving force of hole injection, dye regeneration and charge recombination (ΔG, ΔG and ΔG) of W2-4 are the best, with more negative ΔG (-4.33), ΔG (-1.74) and more positive ΔG (1.92). Replacing 2,1,3-benzothiadiazole with thiazolo[5,4-d]thiazole as π'-spacers is a effective way to improve the performance of the dyes. An introduction of thiazolo[5,4-d]thiazole group can improve the absorption ability and hinder charge recombination. Graphical abstract Absorption spectra of p-type D-π-A sensitizers with modified π-spacers.
基于原型敏化剂W2，我们设计了基于三芳基胺的p型敏化剂W2-1至W2-7，它们包含修饰的π-间隔基（π'）、一个π-间隔基和两个锚定基团。对于W2-1至W2-4，W2中的2,1,3-苯并噻二唑被噻吩并[3,4-b]-1,4-二恶英、噻吩、噻吩并[3,4-c][1,2,5]噻二唑、噻唑并[5,4-d]噻唑作为π'，噻吩作为π-间隔基。对于W2-5至W2-8，π'和π相同，分别以2,1,3-苯并噻二唑、噻吩并[3,4-b]-1,4-二恶英、噻吩并[3,4-c][1,2,5]噻二唑、噻唑并[5,4-d]噻唑作为π'-间隔基。使用密度泛函理论（DFT）和含时DFT（TDDFT）在CAM-B3LYP/6-311G(d,p)水平上计算结构优化、电子能级和吸收特性。采用极化连续介质模型考虑氯仿中的溶剂效应。结果表明，最高占据分子轨道和最低未占据分子轨道保证了足够的空穴注入（低于-0.2 eV）和染料再生（低于-0.2 eV）。W2-4具有更高的光捕获效率（LHE）（0.994），并且与400 nm至600 nm的可见光有更大的重叠。最后，结果表明W2-4的空穴注入、染料再生和电荷复合的驱动力（ΔG、ΔG和ΔG）最佳，ΔG更负（-4.33），ΔG更负（-1.74），ΔG更正（1.92）。用噻唑并[5,4-d]噻唑取代2,1,3-苯并噻二唑作为π'-间隔基是提高染料性能的有效方法。引入噻唑并[5,4-d]噻唑基团可以提高吸收能力并阻碍电荷复合。图形摘要：具有修饰π-间隔基的p型D-π-A敏化剂的吸收光谱。
