Premium
Modulation of the cis ‐ and trans ‐Conformations in Bis‐ o ‐carborane Substituted Benzodithiophenes and Emission Enhancement Effect on Luminescent Efficiency by Solidification
Author(s) -
Nishino Kenta,
Uemura Kyoya,
Tanaka Kazuo,
Morisaki Yasuhiro,
Chujo Yoshiki
Publication year - 2018
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201701641
Subject(s) - carborane , chemistry , substituent , quenching (fluorescence) , luminescence , ring (chemistry) , aggregation induced emission , stereochemistry , amorphous solid , solid state , molecule , crystallography , photochemistry , medicinal chemistry , organic chemistry , fluorescence , physics , optoelectronics , quantum mechanics
Bis‐carborane‐substituted benzo[1,2‐ b :4,5‐ b′ ]dithiophenes (DCB‐R, where R = H, t Bu) were synthesized and characterized. Their three‐dimensional conformations were tuned by introducing the tert ‐butyl substituent at the para ‐positions of the phenyl rings. Both molecules showed emission enhancement behavior, especially in the solid state. The emission quantum efficiencies were over 0.90 in the crystalline state. Moreover, it was shown that the efficiency of DCB‐ t Bu was over 0.70 in the amorphous state. From structural analyses and mechanistic investigations, it was proposed that the tert ‐butyl substituents play a critical role in the formation of the trans ‐conformation followed by suppression of aggregation‐caused quenching because of the o ‐carborane units located at each plane of the benzodithiophene ring.