A Macrocyclic Fluorophore Dimer with Flexible Linkers: Bright Excimer Emission with a Long Fluorescence Lifetime.
Bright fluorescent molecules with long fluorescence lifetimes are important for the development of lifetime-based fluorescence imaging techniques. Herein, a molecular design is described for simultaneously attaining long fluorescence lifetime (τ) and high brightness (ΦF ×ɛ) in a system that features macrocyclic dimerization of fluorescent π-conjugated skeletons with flexible linkers. An alkylene-linked macrocyclic dimer of bis(thienylethynyl)anthracene was found to show excimer emission with a long fluorescence lifetime (τ≈19 ns) in solution, while maintaining high brightness. A comparison with various relevant derivatives revealed that the macrocyclic structure and the length of the alkylene chains play crucial roles in attaining these properties. In vitro time-gated imaging experiments were conducted as a proof-of-principle for the superiority of this macrocyclic fluorophore relative to the commercial fluorescent dye Alexa Fluor 488.
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Hiroshi
H
Osaki
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.|Department of Applied Chemistry, National University of Kaohsiung, 700 Kaohsiung University Road, Kaohsiung, 811, Taiwan.
Chih-Ming
CM
Chou
Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan. taki@itbm.nagoya-u.ac.jp.
Masayasu
M
Taki
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Kai
K
Welke
Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Daisuke
D
Yokogawa
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan. sirle@chem.nagoya-u.ac.jp.|Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan. sirle@chem.nagoya-u.ac.jp.
Stephan
S
Irle
Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Yoshikatsu
Y
Sato
Division of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.|Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Tetsuya
T
Higashiyama
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Shohei
S
Saito
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan.
Aiko
A
Fukazawa
Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan. yamaguchi@chem.nagoya-u.ac.jp.|Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya, 464-8602, Japan. yamaguchi@chem.nagoya-u.ac.jp.
Shigehiro
S
Yamaguchi
excimer; fluorescence; imaging agents; photophysics; pi conjugation