Mori Hakan, Nakazato Ryosuke, Tachibana Hiroshi, Shimada Tetsuya, Ishida Tamao, Ryo Miyajima, Hasegawa Eietsu, Takagi Shinsuke
Department of Applied Chemistry for Environment, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji-Shi, Tokyo, 192-0397, Japan.
Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-NE-2 Ookayama, Meguro-Ku, Tokyo, 152-8550, Japan.
Photochem Photobiol Sci. 2024 Jun;23(6):1077-1086. doi: 10.1007/s43630-024-00576-9. Epub 2024 Apr 28.
The photophysical behaviors of benzimidazolium derivative [4-(1,3-dimethylbenzimidazol-3-imu-2-yl)-N, N-diphenylaniline (2-(4-(diphenylamino)phenyl)-1,3-dimethyl-1H-benzo[d]imidazol-3-ium)] (BID) in water, organic solvents and on synthetic saponite were investigated. The fluorescence quantum yield (Φ) of BID was 0.91 on the saponite surface under the optimal condition, while that in water was 0.010. Such fluorescence enhancement on the inorganic surface is called "surface-fixation induced emission (S-FIE)". This fluorescence enhancement ratio for BID is significantly high compared to that of conventional S-FIE active dyes. From the values of Φ and the excited lifetime, the non-radiative deactivation rate constant (k) and radiative deactivation rate constant (k) of BID on the saponite surface and in water were determined. Results showed that the factors for fluorescence enhancement were both the increase of k and the decrease of k on the saponite surface; especially, k decreased by more than two orders due to the effect of nanosheets.
