POS5-0807
Controlling Unusual NIR Red-Shifted Absorption in Quinoid-Based Chiral π-Conjugated Molecules through Side-Chain Engineering
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Jeongjin Hong (Gwangju Institute of Science and Technology)
Co-Author(s)
Abstract
The development of organic π-conjugated chiral materials with near-infrared (NIR) optical and chiroptical responses is important for expanding circularly polarized light (CPL)-responsive optoelectronic applications such as encryption, CPL imaging. In π-conjugated molecular systems, these long-wavelength responses are strongly governed by intermolecular packing and supramolecular chiral assembly. Therefore, subtle structural parameters, such as side-chain length, can play a critical role in controlling aggregation behavior, molecular stacking distance, and film-state organization. In particular, side-chain engineering offers a useful strategy for modulating aggregation behavior and supramolecular organization in planar quinoid-based chiral molecules, thereby influencing their long-wavelength optical and chiroptical responses.
In this work, we investigated a series of quinoid-based chiral π-conjugated molecules, bQPheDOT-(S)-C8, bQPheDOT-(S)-C12, and bQPheDOT-(S)-C18, to understand how side-chain length affects unusual long-wavelength absorption and supramolecular chiroptical properties. Notably, bQPheDOT-(S)-C12 exhibited an unusual film-state red-shifted absorption band extending to approximately 1030 nm in the NIR-II region, accompanied by a corresponding chiroptical response. Although bQPheDOT-(S)-C8 and bQPheDOT-(S)-C18 also showed red-shifted absorption in the aggregated or film state, their spectral shifts were less pronounced than that of bQPheDOT-(S)-C12. Comparative optical, chiroptical, and morphological analyses revealed that subtle changes in side-chain length can alter film-state molecular organization and supramolecular chiral assembly. These results provide insight into the side-chain-dependent design of quinoid-based chiral materials for controlling unusual NIR absorption and long-wavelength chiroptical responses.
In this work, we investigated a series of quinoid-based chiral π-conjugated molecules, bQPheDOT-(S)-C8, bQPheDOT-(S)-C12, and bQPheDOT-(S)-C18, to understand how side-chain length affects unusual long-wavelength absorption and supramolecular chiroptical properties. Notably, bQPheDOT-(S)-C12 exhibited an unusual film-state red-shifted absorption band extending to approximately 1030 nm in the NIR-II region, accompanied by a corresponding chiroptical response. Although bQPheDOT-(S)-C8 and bQPheDOT-(S)-C18 also showed red-shifted absorption in the aggregated or film state, their spectral shifts were less pronounced than that of bQPheDOT-(S)-C12. Comparative optical, chiroptical, and morphological analyses revealed that subtle changes in side-chain length can alter film-state molecular organization and supramolecular chiral assembly. These results provide insight into the side-chain-dependent design of quinoid-based chiral materials for controlling unusual NIR absorption and long-wavelength chiroptical responses.
