Abstract Summary/Description
Donor–π-acceptor (D–π-A) fluorophores are organic molecules that consist of a donor unit, a conjugated π-bridge, and an acceptor unit. This structure allows for efficient intramolecular charge transfer (ICT) between the donor and acceptor through the π-bridge, resulting in strong fluorescence emission and customizable optical properties. By altering the donor, acceptor, or π-bridge, we can fine-tune the fluorophores' quantum yields, chemical properties, and emission wavelengths, which can range from ultraviolet-visible (UV-Vis) light (400–650 nm) to near-infrared (NIR) regions, including NIR-I (650–900 nm) and NIR-II (1000–1500 nm). These fluorophores are of great interest due to their unique photophysical characteristics, making them promising candidates for biomedical and bioimaging applications. This research presents the synthesis, characterization, and photochemical properties of various D–π-A analogs composed of malonic acid and indanedione derivatives as the acceptor and various indole derivatives, connected by a Vilsmeier-Haack linker. This work builds on ongoing studies in our laboratory aimed at enhancing the properties of donor–π-acceptor fluorophores for future bioimaging applications
