Switching of Two‐Photon Optical Properties by Anion Binding of Pyrrole‐Based Boron Diketonates through Conformation Change

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...

Full description

Saved in:
Bibliographic Details
Published in:Chemistry : a European journal 2020-03, Vol.26 (15), p.3404-3410
Main Authors: Kita, Hanayo, Yamakado, Ryohei, Fukuuchi, Risa, Konishi, Tatsuki, Kamada, Kenji, Haketa, Yohei, Maeda, Hiromitsu
Format: Article
Language:English
Subjects:
Absorption
anion binding
Anions
Binding
Boron
Chemical sensors
Chemical speciation
Chemistry
Conformation
conformation changes
Dipole moments
Dyes
Electronic systems
External stimuli
Fluorescence
Medical imaging
non-linear optics
Optical properties
Photon absorption
Photons
sensors
two-photon absorption
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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. Binding changes: Dipyrrolyldiketone BF2 complexes substituted with π‐extended units were used as anion‐regulated systems with efficient two‐photon optical properties (two‐photon absorption and two‐photon‐excited fluorescence). A significant decrease in the transition dipole moments upon anion binding was caused by conformation changes and was the key factor for controlling the observed two‐photon optical properties.
ISSN:0947-6539
1521-3765
DOI:10.1002/chem.201905467