Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2017-12-01

Journal: DYES AND PIGMENTS

Included Journals: EI、SCIE、Scopus

Volume: 147

Page Number: 465-475

ISSN: 0143-7208

Key Words: AIEE; Triarylcyclopentadiene derivatives; Crystal structures; Fluorescence; OLEDs

Abstract: Five highly efficient blue-emitting triarylcyclopentadiene derivatives 1-5 were designed and synthesized by introducing phenyl, methoxyphenyl, methoxybiphenyl and methoxynaphthyl groups to cyclopentadiene backbone, respectively. These compounds possess good thermal stability with decomposition temperatures of 264-340 degrees C and exhibit intense blue fluorescence with maximum emission peaked at 457-470 nm. All compounds emit weak fluorescence in solution, but they become strong emitters in the aggregated state indicating typical aggregation-induced emission enhancement (AIEE) properties. AIEE behaviour was further confirmed by fluorescent changes depended on temperature and solution viscosity as well as time-resolved fluorescence lifetime measurements. Unexpected substituent effect on aggregation structures and fluorescent properties of 1-5 was also observed. Single-crystal structure analysis revealed that highly twisted conformations and bulky substituents on cyclopentadiene core could dramatically suppress the intermolecular pi-pi interactions leading to intense blue emission of these compounds in aggregates. Furthermore, the non-doped and doped organic light-emitting diodes (OLEDs) using compounds 2 and 5 as the emitting layers have been fabricated, respectively. A non-doped OLED with compound 5 displays good electroluminescent performance with a light-blue emission and a maximum luminance of 3886 cd/m(2). (C) 2017 Elsevier Ltd. All rights reserved.