A novel strategy for the synthesis of triphenylamine based and methoxy supported deep red emitting push-pull chromophores is developed. The methoxy groups though not in conjugation with the acceptor exhibited a red shifted absorption and emissions (670 nm) as compared to the unsubstituted analogues due to the improved donating ability of triphenylamine. The dyes show high molar extinction coefficients (1, 65,800 M⁻¹ cm⁻¹) and as the number of withdrawing groups increases the molar extinction coefficient and emission intensity increase. Positive solvatochromism (96 nm) was observed which is well supported by linear and multi-linear regression. The mono styryl dyes showed enhancement of fluorescence while the di and tri-styryl dyes show quenching of fluorescence in polar solvents, which is correlated with the intramolecular charge transfer and twisted intramolecular charge transfer. Viscosity induced emission enhancement has also been observed. The experimental findings were correlated theoretically by using Density Functional theory computations.

中文翻译：

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甲氧基负载的深红色发光单，双和三三苯胺-异佛尔酮基苯乙烯基着色剂：合成，光物理性质，ICT，TICT发射和粘度敏感性

开发了一种新的合成三苯胺基和甲氧基负载的深红色发射推挽发色团的策略。与未取代的类似物相比，尽管未与受体结合，但由于三苯胺的提高的供体能力，甲氧基显示出红移的吸收和发射（670nm）。染料显示高摩尔消光系数（1，65,800 M ^-1 cm ^-1），并且随着撤离基团的数量增加，摩尔消光系数和发射强度增加。观察到正溶剂光致变色（96 nm），线性和多线性回归很好地支持了这一现象。单苯乙烯基染料显示增强的荧光，而二苯乙烯基和三苯乙烯基染料显示在极性溶剂中的荧光猝灭，这与分子内电荷转移和扭曲的分子内电荷转移相关。还观察到了粘度引起的发射增强。通过使用密度泛函理论计算，将实验结果与理论进行了关联。