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Switching of Two-Photon Optical Properties by Anion Binding of Pyrrole-Based Boron Diketonates through Conformation Change |
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| Authors: | Hanayo Kita Dr Ryohei Yamakado Risa Fukuuchi Tatsuki Konishi Dr Kenji Kamada Dr Yohei Haketa Prof Hiromitsu Maeda |
| Affiliation: | 1. Inorganic Functional Materials Research Institute (IFMRI), National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, 563-8577 Japan
Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, Sanda, 669-1337 Japan;2. Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yonezawa, 992-8510 Japan;3. Inorganic Functional Materials Research Institute (IFMRI), National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, 563-8577 Japan;4. Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, Kusatsu 5, 25-8577 Japan |
| Abstract: | Two-photon absorption (TPA) dyes with intense fluorescence can be used to detect small chemical species and as sensors and bioimaging probes for specific analytes. Various TPA dyes responding to a number of external stimuli have been reported. Among them, biologically important anionic species have not been used as agents to control TPA properties because their direct electronic influences on the transition dipole moments of dyes are typically small. In this study, dipyrrolyldiketone BF2 complexes substituted with π-extended units exhibited efficient TPA properties that could be regulated by conformation changes induced by anion binding. The TPA intensity decreased to 1/5 of the original intensity upon anion binding, which was much larger than that observed for one-photon absorption. Anion detection was achieved by a change in the emission intensity of spatially resolved spots of two-photon-excited fluorescence (TPEF) in the sample. Experimental and theoretical studies were performed to understand the mechanism of the TPA property control and showed that the drastic changes in the transition dipole moments upon conformation changes between the straight and bending forms of the π-electronic systems caused the TPA and TPEF intensities drop. |
| Keywords: | anion binding conformation changes non-linear optics sensors two-photon absorption |
