Charge transfer (CT) and aggregation-induced emission (AIE) photochromic nanoparticles: Dr. R. Métivier, Pr. K. Matsuda
In this task, novel fluorescent photochromic terarylenes will be investigated, based on an electron-donating group directly bound to the central phenylthiazole unit regarded as an electron-withdrawing group. In such systems, contribution of the charge transfer (CT) character on photophysical properties is expected. Collaborative studies involving the groups of Pr. T. Kawai (NAIST), of ENS Paris-Saclay and Lille Univ. have started in 2015 through the stay of a PhD student from NAIST in France. They aim at studying the photodynamics of novel multifunctional photoactive molecules (coupling photochromism, fluorescence, and charge transfer properties). Within this task, timeresolved spectroscopy measurements, advanced data analyses and NMR studies of ground state species will be performed by Lille Univ. to address the ultrafast photodynamics, and especially strive to solve the influence of the excitation wavelengths and solvents on the kinetics. The final target consists in the control of the switching yields and properties, as well as the photo-dynamics to construct highly responsive switching materials.
Another noteworthy effect, the aggregation-induced emission (AIE), based on intermolecular interactions, will be exploited to create fluorescent nanoparticles. This synergistic phenomenon, arising from the association of a large number of molecules gathered in nanosystem, is particularly interesting when combined with photochromic molecules. Amplified effects in terms of brightness and photoswitching are expected in such nanoarchitectures. In this regard, new photoswitchable molecular systems will be designed, and this typical nano-scale effect will be an important axis of investigation in this axis.