Steering Nanohelix and Upconverted Circularly Polarized Luminescence by Using Completely Achiral Components

• Published in: ACS nano Vol. 15; no. 2; pp. 2753 - 2761
• Main Authors: Zhou, Minghao, Sang, Yutao, Jin, Xue, Chen, Sanxu, Guo, Junchen, Duan, Pengfei, Liu, Minghua
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 23.02.2021
• Subjects: upconverted circularly polarized luminescence; self-assembly; symmetry breaking; photon upconversion; upconversion nanoparticle
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.0c08539

Enormous attention has been paid to upconverted circularly polarized luminescence (UC-CPL). However, so far, chiral species are still needed in UC-CPL materials, either through the covalent or noncovalent bond. Here, we report a general supramolecular coassembly approach for the fabrication of UC-CPL systems from completely achiral components. We have found that an achiral C 3-symmetric molecule could form a chiral nanohelix through symmetry breaking, which could serve as a general helical platform to endow achiral guests with induced chirality and CPL activity. Two different photon upconversion systems, namely, triplet–triplet annihilation photon upconversion (TTA-UC) donor/acceptor pairs and inorganic lanthanide upconversion nanoparticles (UCNPs), are selected. When these two systems coassembled with the chiral nanohelix made from an achiral C 3-symmetric molecule, hybrid nanohelix structures formed and UC-CPL activity was induced. Through such an approach, we demonstrated that the fabrication of the UC-CPL materials does not require any chiral molecules. Moreover, we have shown that the polarization of UC-CPL can be tuned by the helicity of the nanohelix, which could be controlled through the seeded vortex. Our work provides a general approach for designing tunable UC-CPL materials from completely achiral motifs, which largely expands the research scope of the CPL materials.