A Luminescent Nitrogen-Containing Polycyclic Aromatic Hydrocarbon Synthesized by Photocyclodehydrogenation with Unprecedented Regioselectivity.
We present a nitrogen-containing polycyclic aromatic hydrocarbon (N-PAH), namely 12-methoxy-9-(4-methoxyphenyl)-5,8-diphenyl-4-(pyridin-4-yl)pyreno[1,10,9-h,i,j]isoquinoline (c-TPE-ON), which exhibits high quantum-yield emission both in solution (blue) and in the solid state (yellow). This molecule was unexpectedly obtained by a three-fold, highly regioselective photocyclodehydrogenation of a tetraphenylethylene-derived AIEgen. Based on manifold approaches involving UV/Vis, photoluminescence, and NMR spectroscopy as well as HRMS, we propose a reasonable mechanism for the formation of the disk-like N-PAH that is supported by density functional theory calculations. In contrast to most PAHs that are commonly used, our system does not suffer from entire fluorescence quenching in the solid state due to the peripheral aromatic rings preventing π-π stacking interactions, as evidenced by single-crystal X-ray analysis. Moreover, its rod-like microcrystals exhibit excellent optical waveguide properties. Hence, c-TPE-ON comprises a N-PAH with unprecedented luminescent properties and as such is a promising candidate for fabricating organic optoelectronic devices. Our design and synthetic strategy might lead to a more general approach to the preparation of solution- and solid-state luminescent PAHs.
HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057 (P.R. China).|Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Xinggui
X
Gu
HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057 (P.R. China).|Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Hong
H
Wang
HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057 (P.R. China).|Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Jesse
J
Roose
HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057 (P.R. China).|Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Zikai
Z
He
Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (P.R. China).
Yue
Y
Zhou
Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (P.R. China).
Yongli
Y
Yan
HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057 (P.R. China).|Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Yuanjing
Y
Cai
Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Heping
H
Shi
Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Yilin
Y
Zhang
Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Herman H Y
HH
Sung
HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057 (P.R. China).|Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Jacky W Y
JW
Lam
Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (P.R. China).
Qian
Q
Miao
Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (P.R. China).
Yongsheng
Y
Zhao
Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Kam Sing
KS
Wong
Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China).
Ian D
ID
Williams
HKUST-Shenzhen Research Institute, No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan, Shenzhen, 518057 (P.R. China). tangbenz@ust.hk.|Departments of Chemistry, Physics, and Division of Life Science, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (P.R. China). tangbenz@ust.hk.|Guangdong Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 51640 (P.R. China). tangbenz@ust.hk.
Ben Zhong
BZ
Tang
aggregation; luminescence; optical waveguides; polycycles; regioselectivity