A novel phenothiazine derivative conjugated with vinylcyclohexenyl‐malononitrile (PTZ‐CDN) was synthesized through the Knoevenagel reaction of 10‐octyl‐10H‐phenothiazine‐3,7‐dicarbaldehyde with 2‐(3,5,5‐trimethylcyclohex‐2‐en‐1‐ylidene)‐malononitrile and fully characterized. The UV–vis absorption spectra of PTZ‐CDN in different solvents showed a λ_max band at 497–531 nm with a high molar extinction coefficient attributed to intramolecular charge transfer (ICT) with the characteristics of a π–π* transition. Increasing the solvent polarity resulted in a bathochromic shift of λ_max. The PTZ‐CDN fluorescence emission spectra were more sensitive to increasing the solvent polarity than the absorption spectra; they displayed a blue shift of λ_em by 85 nm. To understand the behaviour of the PTZ‐CDN derivative, Stokes' shift ( with respect to the solvent polarity, Lippert–Mataga and linear solvation–energy relationship (LSER) models were applied in which the LSER showed better regression than the Lippert–Mataga plots (r² = 0.9627). Finally, the TD‐density functional theory (DFT) electronic transition spectra in dioxane and dimethyl formamide (DMF) were calculated. The DFT data showed that λ_max resulted from the support of the highest occupied molecular orbital to the lowest unoccupied molecular orbital transition with 74% and 99% in dioxane and DMF, respectively.

中文翻译：

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吩噻嗪花序乙烯基环己烯基丙二腈的合成，光物理性质和密度泛函理论研究

通过10-辛基-10 H-吩噻嗪-3,7-二甲醛与2-（3,5,5-三甲基环己基-2-en ）的Knoevenagel反应合成了与乙烯基环己烯基-丙二腈（PTZ-CDN）共轭的新型吩噻嗪衍生物-1-亚丙基）-丙二腈并充分表征。在不同溶剂中PTZ-CDN的紫外可见吸收光谱显示在497-531 nm处有一个λ_最大谱带，其高消光系数归因于分子内电荷转移（ICT），具有π-π*跃迁的特征。溶剂极性的增加导致_λmax的红移。PTZ-CDN荧光发射光谱比吸收光谱对增加溶剂极性更敏感。他们显示出_λem的蓝移85 nm。为了了解PTZ-CDN衍生物的行为，应用了斯托克斯位移（ 关于溶剂极性，Lippert-Mataga和线性溶剂化-能量关系（LSER）模型，其中LSER显示出比Lippert-Mataga图更好的回归（r ² = 0.9627）。最后，计算了二恶烷和二甲基甲酰胺（DMF）中的TD密度泛函理论（DFT）电子跃迁谱，DFT数据表明_λmax是由最高占据分子轨道的最低的未占据分子轨道跃迁，二恶烷和DMF分别为74％和99％。