Bajpai Shubham, Behera Raghu Nath
Department of Chemistry, Birla Institute of Technology and Science, Pilani - K. K. Birla Goa Campus, Zuarinagar, 403726, Goa, India.
J Mol Model. 2025 Jan 22;31(2):59. doi: 10.1007/s00894-025-06283-1.
Donor-acceptor (D-A) complexes, formed between two or more molecules held together by intermolecular forces, show interesting tunable properties and found applications in diverse fields, including semiconductors, catalysis, and sensors. In this study, we investigated the D-A complexes formed between perylene and 7,7,8,8-tetracyanoquinodimethane (TCNQ) and their chalcogen (S, Se) and fluorine derivatives. It was observed that interaction energies due to complex formation increase while the HOMO-LUMO gaps decrease with chalcogen substitutions. A redshift in the electronic absorption spectra of the complexes was observed with chalcogen substitutions. The substitution of fluorine further enhanced these changes without altering the trend. These changes were found to be more for substitution with selenium compared to that of sulfur.
The ωB97X-D/6-311+G(2df,p) level of theory was used to optimize the individual geometries, complexes, and for the frequency calculation. Atoms-in-molecule and reduced density gradient analyses were employed for the interaction study. Time-dependent density functional theory with the same level was used to analyze the electronic excitation for complexes.
供体-受体（D-A）复合物由两个或多个通过分子间力结合在一起的分子形成，具有有趣的可调谐性质，并在包括半导体、催化和传感器在内的多个领域得到应用。在本研究中，我们研究了苝与7,7,8,8-四氰基对苯二醌二甲烷（TCNQ）及其硫族元素（S、Se）和氟衍生物形成的D-A复合物。观察到，随着硫族元素取代，由于复合物形成导致的相互作用能增加，而最高占据分子轨道-最低未占据分子轨道（HOMO-LUMO）能隙减小。随着硫族元素取代，复合物的电子吸收光谱出现红移。氟的取代进一步增强了这些变化，且不改变趋势。与硫取代相比，硒取代时这些变化更大。
采用ωB97X-D/6-311+G(2df,p)理论水平来优化单个几何结构、复合物，并进行频率计算。采用分子中的原子和密度降低梯度分析进行相互作用研究。使用相同水平的含时密度泛函理论来分析复合物的电子激发。
