Switchable Intersystem Crossing (sISC) in Organic Dyes: Unlocking Dynamic Photonic Properties
Year: 2025
Type: article
Abstract: Switchable intersystem crossing (sISC) is a novel concept in the design of functional dyes that enables dynamic modulation of fluorescence and triplet state formation in response to changes in the dye's environment. Unlike conventional dyes, where intersystem crossing and fluorescence rates are entirely determined by molecular structure, sISC dyes allow reversible switching between these functions based on external factors, such as solvent polarity. sISC can arise from various photophysical mechanisms involving charge–transfer states, whose energies are sensitive to the surrounding environment. Mechanisms such as thermally activated delayed fluorescence and spin–orbit charge transfer intersystem crossing can be employed to design sISC dyes. The ability to fine‐tune photophysical processes without chemical modification of the dye's structure opens new possibilities for biomedical applications, including bioimaging, photodynamic therapy, and optogenetic control. This paper introduces the concept of sISC, provides key examples of dyes exhibiting this behavior, and discusses approaches for their design.
Source: ChemPhotoChem
Authors: Mikhail A. Filatov, Metodej Dvoracek
Institution: Technological University Dublin
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,030
OpenAlex ID: W4415029032