Controlling Two-Photon Action Cross Section by Changing a Single Heteroatom Position in Fluorescent Dyes
Borys Ośmiałowski, Elizaveta F. Petrusevich, Magda A. Antoniak, Izabela Grela, Mohammed Bin Jassar, Marcin Nyk, Josep M. Luis, Beata Jędrzejewska, Robert Zaleśny, Denis Jacquemin
Abstract
The optimization of nonlinear optical properties for "real-life" applications remains a key challenge for both experimental and theoretical approaches. In particular, for two-photon processes, maximizing the two-photon action cross section (TPACS), the figure of merit for two-photon bioimaging spectroscopy, requires simultaneously controlling all its components. In the present Letter, a series of difluoroborates presenting various heterocyclic rings as an electron acceptor have been synthesized and their absorption, fluorescence, photoisomerization, and two-photon absorption features have been analyzed using both experimental and theoretical approaches. Our results demonstrate that the TPACS values can be fine-tuned by changing the position of a single heteroatom, which alters the fluorescence quantum yields without changing the intrinsic two-photon absorption cross section. This approach offers a new strategy for optimizing TPACS.