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Updated: Jun 19, 2026
Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Circularly polarized luminescence of Eu(III) complexes with point- and axis-chiral ligands dependent on coordination
Takashi Harada1, Yoko Nakano, Michiya Fujiki
1Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-Cho, Ikoma, Nara 630-0192, Japan.
Abstract:
Circularly polarized luminescence (CPL) of Eu(III) complexes with point- and axis-chiral ligands, [Eu((R/S)-BINAPO)(D-facam)(3)] ((R/S)-BINAPO, (R/S)-2,2'-bis(diphenylphosphoryl)-1,1'-binaphthyl; D-facam, 3-trifluoroacetyl-d-camphor), [Eu(BIPHEPO)(D-facam)(3)] (BIPHEPO, 2,2'-bis(diphenylphosphoryl)-biphenyl), [Eu(TPPO)(2)(D-facam)(3)] (TPPO, triphenylphosphine oxide), and [Eu((R)-BINAPO)(hfa)(3)] (hfa, 1,1,1,5,5,5-hexafluoropentane-2,4-dione) are reported. The photophysical properties of chiral Eu(III) complexes were characterized by circular dichroism spectra, emission spectra, emission quantum yields, emission lifetimes, and CPL spectra. The dissymmetry factors of their CPL (|g(CPL)|) at the magnetic-dipole transition of [Eu((R)-BINAPO)(D-facam)(3)], [Eu((S)-BINAPO)(D-facam)(3)], [Eu(BIPHEPO)(D-facam)(3)], and [Eu(TPPO)(2)(D-facam)(3)] were as high as 0.44, 0.34, 0.24, and 0.47, respectively, while [Eu((R)-BINAPO)(hfa)(3)] exhibited a relatively smaller dissymmetry factor (|g(CPL)| = 0.03). Their coordination structures were determined by the X-ray single-crystal analyses with shape-measure estimations. The photophysical relationship between the CPL properties and the electric transition probabilities of the chiral Eu(III) complexes is elucidated in terms of the coordination structures.
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