three. Since the two constrained derivatives cannot twist about the amino group, they must emit from a planar intramolecular charge-transfer excited state. The similar photophysical behavior suggests that dansyl also emits from a PICT excited state instead of a twisted intramolecular charge transfer state.
将其中
氨基被限制在环中的丹磺酰基(1-二甲基
氨基-5-
萘磺酰基)的两种衍
生物制备为
新戊酯。将它们的光物理行为与
丹磺酸酯进行比较。三种的溶剂变色和量子产率都相似。由于两个受约束的衍
生物不能绕
氨基扭转,因此它们必须从平面分子内电荷转移激发态发射。类似的光物理行为表明,丹磺酰也从
PICT激发态发射,而不是扭曲的分子内电荷转移态。