Green, sustainable syntheses of various squaraine dyes and their applications as environment-sensitive probes & dual-state emitters

Ta, Daniel Duy

Publication

Green, sustainable syntheses of various squaraine dyes and their applications as environment-sensitive probes & dual-state emitters

Ta, Daniel Duy

Date

2024-05-06

Abstract

Squaraine dyes, distinguished by their distinctive donor-acceptor-donor molecular architecture, represent a class of small photoluminescent molecules with broad applicability across the realms of physical sciences, medicine, and engineering. Despite considerable research devoted to these dyes, the development of efficient, modular, and environmentally benign synthetic routes to squaraines remains unexplored. This limitation not only impedes progress in fundamental studies but also hinders the translation of squaraines into practical applications. This dissertation is focused on our investigations into the synthesis, characterization and applications of various types of squaraine dyes. Specifically, several squaraine dyes have been shown to be viable environment-sensitive probes. Furthermore, the general requirements for achieving multiplexing sensing capabilities using these probes have been established. Additionally, our research has revealed that a subset of the synthesized squaraine dyes exhibits dual-state emission, emitting both in solution and in the solid state. Through computational approaches, we have elucidated the mechanisms underlying this dual-state emission phenomenon. To capitalize on the novel and intriguing properties of these dyes, considerable efforts have been devoted to developing facile, efficient, scalable, and sustainable synthetic strategies. These strategies aim to produce a diverse range of structurally and functionally distinct squaraine dyes with enhanced properties, thereby broadening their potential applications.