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1,2,5‐Triphenylpyrrole Derivatives with Dual Intense Photoluminescence in Both Solution and the Solid State: Solvatochromism and Polymorphic Luminescence Properties
Author(s) -
Li Yuanyuan,
Lei Yunxiang,
Dong Lichao,
Zhang Longlong,
Zhi Junge,
Shi Jianbing,
Tong Bin,
Dong Yuping
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201804074
Subject(s) - solvatochromism , luminophore , luminescence , photoluminescence , intramolecular force , photochemistry , chemistry , polar effect , electron transfer , solvent , materials science , stereochemistry , organic chemistry , optoelectronics
Abstract Five organic luminophores, 1,2,5‐triphenylpyrrole (TPP) derivatives 3 a – e bearing electron‐withdrawing or electron‐donating groups, have been synthesized by Pd‐catalyzed Suzuki coupling of 1‐phenyl‐2,5‐di(4′‐bromophenyl)pyrrole and para ‐substituted phenylboronic acid derivatives. They possess good thermal stabilities with high decomposition temperatures above 310 °C. Investigation of the photophysical properties of the luminogens 3 a – e indicated that they exhibited dual intense photoluminescence in both solution and the solid state due to their twisted conformations, and their fluorescence quantum yields ( Φ F ) were determined as 68.7–94.9 % in THF solution and 19.1–52.0 % in solid powder form. Compounds 3 a – c bearing electron‐accepting groups exhibited remarkable solvatochromism with large Stokes shifts, attributable to their D‐π‐A structure and intramolecular charge‐transfer effect. In particular, 3 a , bearing aldehyde groups, displayed an obvious red‐shift of the emission band from 445 to 564 nm with increasing solvent polarity. However, no obvious solvatochromic behavior was observed for compounds 3 d , e bearing electron‐donating groups. The luminophore 3 a exhibited polymorphic luminescence properties and crystallization‐induced emission enhancement.