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Hydrogen-Bond-Induced Switching of Interaction Hierarchy in Dipolar D-A Chromophores for NIR Circularly Polarized
Laiwei Gao1, Ruilong Zhang1, Ziyi Zhang2
1State Key Laboratory of Precision and Intelligent Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, P. R. China.
Abstract:
Dipolar donor-acceptor (D-A) chromophores exhibit strong near-infrared (NIR) absorption but are intrinsically biased toward electrostatically complementary hetero-association-a packing mode that inherently suppresses chiroptical responses. Here, we show that this preference can be overcome through hydrogen-bond-induced switching of the interaction hierarchy governing supramolecular assembly. In croconaine-based dipolar D-A chromophores, the introduction of directional amide-mediated hydrogen bonding establishes a thermodynamically favored homo-association that overrides dipolar complementarity, thereby switching the preferred packing mode from hetero- to homo-organization. This interaction hierarchy switching drives cooperative homochiral assembly and enables amplified NIR chiroptical responses. Integration of these assemblies into heterojunction devices translates the supramolecular structural reorganization into helicity-dependent electrical outputs, affording efficient NIR circularly polarized photodetection. These results identify interaction hierarchy inversion as an effective strategy for controlling association modes and chiroptical functions in dipolar chromophores.
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