Charge Separation in Excited States of Decoupled Systems—TICT Compounds and Implications Regarding the Development of New Laser Dyes and the Primary Process of Vision and Photosynthesis

TLDR

Dual fluorescence in certain aromatic systems has recently been better understood. The authors aim to use unified theoretical models to explain photophysical behavior across organic, inorganic, and biological compounds, enabling new tailor‑made fluorescent dyes and deeper insight into vision and photosynthesis. The models describe excited‑state twisting of both single‑bond TICT compounds and double‑bond olefins within a single framework. Large charge separation is associated with a twisted or small‑overlap chromophore arrangement, and the models predict photophysical behavior that can guide the design of novel fluorescent materials.

Abstract

Abstract The understanding of the dual fluorescence of certain aromatic systems has greatly advanced in recent years. The accompanying large charge separation has been shown to be linked to a twisted (or small overlap) arrangement of the chromophores. Recent theoretical models are able to describe the excited‐state twisting of both single bonds (TICT compounds) and double bonds (olefins) in a unified picture. These models can help to elucidate the photophysical behavior of many organic, inorganic, and biologically relevant compounds, and their application to laser dyes and fluorescent probes provides a route to new “tailor‐made” fluorescent materials. Applied to the primary processes of vision and photosynthesis, these models can lead to a deeper understanding of basic photobiological processes.