Isomers of Pyrene–Imidazole Compounds: Synthesis and Configuration Effect on Optical Properties

Two
pyrene-imidazole-based structural isomers, axisymmetric syn-PyDTI and centrosymmetric anti-PyDTI,
have been easily produced and successfully separated in a one-pot
reaction. Crystalline syn-PyDTI exhibited a 2-fold
higher quantum efficiency than anti-PyDTI and displayed
a much better performance in OLEDs with a ηc.max of
11.4 cd A–1 (8.8 cd A–1 for anti-PyDTI), although they possess the same apparent electronic
structure. Observations revealed that the molecular excited-state
properties are derived from distinct structural symmetries.

基于吡咯啉咪唑的两种结构异构体——轴对称的 syn-PyDTI 和中心对称的 anti-PyDTI，已在单步反应中轻松合成并成功分离。结晶态的 syn-PyDTI 表现出比 anti-PyDTI 高出两倍的量子效率，并在有机发光二极管 (OLED) 中展现出更佳的性能，其最大外量子效率 ηc.max 达到 11.4 cd A–1（而 anti-PyDTI 为 8.8 cd A–1），尽管它们具有相同的表面电子结构。观察表明，分子的激发态性质源于不同的结构对称性。