molecules investigated exhibit pronounced positive polarity dependent solvatochromic shifts of up to ∼141 nm. Strong fluorescence quantum yields are also observed for dienes containing carbazole and diphenylamine donors. This behavior suggests the presence of highly polar emitting states as a result of π -π* intramolecular charge-transfer (ICT). The observations were corroborated by a linear relation of
描述了一系列供体-π-受体体系的合成和光谱学研究,该体系包含
吡啶作为吸电子基团和
氨基衍
生物(二甲基
氨基,二苯
氨基,
咔唑和julolidine)作为给电子基团,并通过π-间隔基隔开。在不同溶剂中研究了不同供体对吸收和发射性质的影响。所有研究的分子均显示出高达141 nm的明显的与极性相关的溶剂化色移。对于含有
咔唑和
二苯胺供体的二烯,也观察到强的荧光量子产率。该行为表明由于π-π*分子内电荷转移(ICT)导致存在高极性发射态。荧光最大值(νmax)与Lippert-Mataga相关性的溶剂极性函数(Δf)的关系。发射寿命显示出与在激发态下形成一种(1和3)以及两种(2和4)相一致的衰减曲线。