Key Words:ACTIVATED DELAYED FLUORESCENCE; LIGHT-EMITTING-DIODES; PHOTOSENSITIZERS; DESIGN

Abstract:Intersystem crossing (ISC) of triple photosensitizers (PSs) often hinges on enhanced spin-orbit coupling (SOC), typically achieved by incorporating heavy atoms or designing orthogonal donor-acceptor (D-A) dyads. Herein, we explore the synergistic potential of both strategies by integrating a heavy atom and an orthogonal D-A structure within a single PS framework. Specifically, orthogonal heptamethine cyanine (OrT-Cy7-H) is halogenated to yield OrT-Cy7-Cl and OrT-Cy7-Br via molecular engineering. Through theoretical calculations and time-resolved spectroscopy, the ISC of OrT-Cy7-Br is confirmed to be derived from the bromine substitution and the nearly orthogonal D-A structure. Interestingly, the incorporation of bromine enhances molecular aggregation and promotes non-radiative decay through intermolecular collisions. When formulated into nanoparticles, OrT-Cy7-Br exhibits efficient combined photodynamic and photothermal therapeutic effects, underscoring the critical role of both molecular structure and intermolecular interactions in shaping the photophysical properties of PSs. These findings offer valuable insights into the design of next-generation PSs for advanced cancer therapy.

Volume:242

Issue:-

Translation or Not:no