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Updated: May 22, 2025
Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Strong upconverted circularly polarized emission from a chiral tetrahedral Yb/Eu cage
Zhiwei Yao1, Ting Gao1, Pengfei Yan1
1Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, China. lihongfeng@hlju.edu.cn.
Abstract:
Upconverted circularly polarized luminescence (UC-CPL) materials have attracted significant attention due to their potential in optical sensing and bioimaging. However, achieving UC-CPL in lanthanide supramolecular systems remains a challenge due to the extended distances between lanthanide ions. Here, enantiopure tetrahedral cages, (Yb/Eu)4L4(R/S-BINAPO)4, are assembled using achiral C3-symmetric ligands, Ln(III) ions and chiral ancillary ligands. Upon 980 nm excitation, the heterometallic tetrahedral cages exhibit strong UC-CPL (glum = 0.22) and high ΦUC of 3.50 × 10-6. Moreover, through femtosecond transient absorption spectroscopy, we reveal that the ligand's triplet state (T1) serves as a critical mediator in the upconversion energy transfer process within the lanthanide complex, facilitating the efficient transfer of energy from the excited state of Yb3+ to the Eu3+ center via the mechanistic pathway Yb** → T1 → Eu*.
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