胆甾醇修饰羟基喹啉锌的聚集诱导荧光蓝移(英文)

Aggregation Induced Fluorescence Blue-Shift of Zinc Bis (8-hydroxyquinoline) Modified with Cholesteryl

用稳态光谱以及皮秒瞬态荧光光谱研究了新型有机电致发光分子胆甾醇修饰羟基喹啉锌(Zn(ChQ)2)的聚集诱导荧光蓝移性质.在Zn(ChQ)2的极性溶剂溶液中,分子激发后会发生从胆甾醇基团向喹啉环的光致电子转移,转移后形成了"扭转的分子内电荷转移态"作为新的荧光发射态.而在薄膜态中,分子由于聚集产生空间位阻,不能形成新的荧光发射态,相对于极性溶剂中,产生聚集荧光增强效应,荧光发射峰会蓝移,发射强度会增强.在薄膜态中,全波长上的超快荧光衰减说明存在分子间光致能量转移过程.

Aggregation induced fluorescence blue-shift of the newly synthesized zinc bis（8-hydroxyquinoline） modified with cholesteryl （Zn（ChQ）2） is studied by static and picosecond transient emission spectroscopy.Fast solvent-induced charge transfer is found when Zn（ChQ）2 is dissolved in polar solvents.The twisted intramolecular charge transfer （TICT） state is formed as new emission state.Its emission spectra of Zn（ChQ）2 in aggregation form （film state） are blue-shifted compared to those in polar solvents.Steric hindrance induced weakened intermolecular interaction in aggregations lead to blue-shifted emission and enhanced quantum efficiency.Intermolecular energy transfer is found in solid film and independent on emission wavelength.