BACKGROUND Donor acceptor moieties connected through π-conjugated bridges i.e. D-π-A, in order to facilitate the electron/charge transfer phenomenon, have wide range of applications. Many classes of organic compounds, such as cyanine, coumarin carbazole, indoline, perylene, phenothiazine, triphenylamine, tetrahydroquinoline and pyrrole can act as charge transfer materials. Phenothiazines have been extensively studied as electron donor candidates due to their potential applications as electrochemical, photovoltaic, photo-physical and DSSC materials. RESULTS Two phenothiazine derivatives, 2-((10-hexyl-10H-phenothiazin-3-yl)methylene)malononitrile (3a) and 2-((10-octyl-10H-phenothiazin-3-yl)methylene)malononitrile (3b) have been synthesized in good yields and characterized by various spectroscopic techniques like FT-IR, UV-vis, (1)H-NMR, (13)C-NMR, and finally confirmed by single crystal X-ray diffraction studies. Density functional theory (DFT) calculations have been performed to compare the theoretical results with the experimental and to probe structural properties. In order to investigate the excited state stabilities the absorption studies have been carried out experimentally as well as theoretically. CONCLUSIONS Compound 3a crystallises as monoclinic, P2 (1)/a and 3b as P-1. The X-ray crystal structures reveal that asymmetric unit contains one independent molecule in 3a, whereas 3b exhibits a very interesting behavior in having a higher Z value of 8 and four independent molecules in its asymmetric unit. The molecular electrostatic potential (MEP) mapped over the entire stabilized geometries of the molecules indicates the potential sites for chemical reactivities. Furthermore, high first hyperpolarizability values entitle these compounds as potential candidates in photonic applications.Graphical abstractPhenothiazines; a comparison of experimental and theoretical analysis.

中文翻译：

---

2-((10-烷基-10H-吩噻嗪-3-基)亚甲基)丙二腈衍生物的合成及结构性质；实验和理论相结合的见解。


背景技术为了促进电子/电荷转移现象，通过π共轭桥即D-π-A连接的供体受体部分具有广泛的应用。许多类别的有机化合物，例如花青、香豆素咔唑、二氢吲哚、苝、吩噻嗪、三苯胺、四氢喹啉和吡咯可以充当电荷转移材料。吩噻嗪由于其作为电化学、光伏、光物理和 DSSC 材料的潜在应用，作为电子给体候选物已被广泛研究。结果 两种吩噻嗪衍生物，2-((10-己基-10H-吩噻嗪-3-基)亚甲基)丙二腈 (3a) 和 2-((10-辛基-10H-吩噻嗪-3-基)亚甲基)丙二腈 (3b)已以良好的产率合成，并通过各种光谱技术（如 FT-IR、UV-vis、(1)H-NMR、(13)C-NMR）进行表征，并最终通过单晶 X 射线衍射研究得到证实。已经进行了密度泛函理论（DFT）计算，以将理论结果与实验结果进行比较并探讨结构特性。为了研究激发态稳定性，已经在实验和理论上进行了吸收研究。结论 化合物 3a 结晶为单斜晶系，P2 (1)/a，3b 结晶为 P-1。 X射线晶体结构表明，3a中的不对称单元包含一个独立分子，而3b表现出一种非常有趣的行为，其不对称单元中具有更高的Z值8和四个独立分子。映射到分子的整个稳定几何形状上的分子静电势 (MEP) 表明了化学反应的潜在位点。 此外，高第一超极化率值使这些化合物成为光子应用中的潜在候选者。实验和理论分析的比较。