Absorption and fluorescence of arylmethylidenoxindoles and isoindigo
作者:Stanislav Luňák、Petra Horáková、Antonín Lyčka
DOI:10.1016/j.dyepig.2009.11.001
日期:2010.5
spectral features of the parent Z-benzylidenoxindole were compared to those of trans-isoindigo and trans-stilbene. Fluorescence of arylmethylidenoxindoles in solution was not observed, as E–Z isomerization represents a dominant deactivation channel after irradiation; when this geometrical isomerization was sterically hindered at low temperature solvent glass or in solid, fluorescence of planar Z-isomers
通过酸或碱催化的取代醛与羟吲哚的缩合反应,合成了一系列芳基甲基亚氨基新吲哚。产物形成为Z-和E-异构体的混合物,使用柱色谱分离并通过1 H和13 C NMR鉴定。基于时间相关的密度泛函理论,通过实验和理论研究了取代基对吸收最大值的影响。溶剂玻璃中的低温吸收光谱能够识别0-0振动带的位置。比较了母体Z-苄亚氨基吲哚的光谱特征与tran s-isoindigo和trans的光谱特征-二苯乙烯。溶液中未观察到芳基甲基亚氨基新多酚的荧光,因为E - Z异构化代表辐照后的主要失活通道。当在低温溶剂玻璃或固体中这种几何异构化在空间上受阻时,观察到平面Z-异构体的荧光。