Self‐Assembled Azo‐Benzothiazole Mesogens: Align the Structure and Follow the Heat to Uncover Anisotropic Photothermal Pathways

Abstract

ABSTRACT Understanding the relationship between molecular structure and anisotropic photothermal behavior is essential for developing light‐responsive materials with directionally controllable behavior. In this study, we report the design of a thiazole‐functionalized azobenzene mesogen, PB‐ABT, which exhibits efficient photothermal conversion under 405 nm light. The introduction of an electron‐rich thiazole moiety induces intramolecular charge transfer (ICT), enhancing π–π stacking and facilitating non‐radiative decay pathways essential for thermal energy generation. Comparative studies with a symmetric reference compound (PB‐Azo) reveal that PB‐ABT exhibits stronger intermolecular interaction, more stable self‐assembly, and significantly improved anisotropic photothermal behavior. The identification of a clear correlation between molecular arrangement and directional photothermal dissipation provides answers to the long‐standing limitations of isotropic behavior and the unclear mechanisms in organic photothermal systems. These anisotropic photothermal properties originate from two key factors: anisotropic surface morphology and direction‐dependent non‐radiative dissipation occurring along π–π stacking pathways, demonstrating a direct link between molecular arrangement and macroscopic heat generation. This work provides a molecular‐level strategy for constructing 405 nm‐responsive organic materials with both optical and thermal anisotropy, offering new insight into the design of aligned photothermal systems for advanced encryptable applications.