White-light emission from a single heavy atom-free molecule with room temperature phosphorescence, mechanochromism and thermochromism

Two heavy atom-free luminophores (SHB t and SDB t) with simple molecular structures have been synthesized Suzuki coupling reactions in which both display white-light emission with prompt fluorescence and room temperature phosphorescence (RTP) in the solid state. The impressive RTP of the luminophore...

Full description

Saved in:
Bibliographic Details
Published in:Chemical science (Cambridge) 2017-03, Vol.8 (3), p.1909-1914
Main Authors: Xu, Bingjia, Wu, Haozhong, Chen, Junru, Yang, Zhan, Yang, Zhiyong, Wu, Yuan-Chun, Zhang, Yi, Jin, Chongjun, Lu, Po-Yen, Chi, Zhenguo, Liu, Siwei, Xu, Jiarui, Aldred, Matthew
Format: Article
Language:English
Subjects:
Emission
Grinding
Hydrogen bonding
Molecular structure
Phosphorescence
Synthesis (chemistry)
Thermochromism
White light
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Two heavy atom-free luminophores (SHB t and SDB t) with simple molecular structures have been synthesized Suzuki coupling reactions in which both display white-light emission with prompt fluorescence and room temperature phosphorescence (RTP) in the solid state. The impressive RTP of the luminophores is produced by a synergistic effect of the strong intermolecular hydrogen bonding in addition to the spin-orbit coupling of the sulfonyl oxygen atoms and the moderate singlet-triplet energy gaps (Δ ). These factors facilitate the intersystem crossing (ISC) process to generate triplet excitons in which the molecular conformations become immobilized to effectively suppress radiationless decay. Under the stimuli of mechanical force and solvent vapor, the RTP of SHB t and SDB t can be simply turned off and on by breaking and reforming the robust hydrogen bonding, which leads to remarkable and reversible mechanochromism between white and deep-blue emission. Moreover, two different thermochromic processes have been observed for the pristine and ground samples of SDB t, in which a tricolor switching system between white, deep-blue and blue emission has been successfully achieved through the sequential control of grinding, heating and fuming. From detailed studies we have determined that the mechanism for the thermochromism of SDB t is correlated with the rearrangement of the white-light emitting molecules to a new packing mode without RTP emission.
ISSN:2041-6520
2041-6539
DOI:10.1039/c6sc03038f