Chiral Tetrakis Eu(III) Complexes with Ammonium Cations for Improved Circularly Polarized Luminescence

Makoto Tsurui; Ryohei Takizawa; Yuichi Kitagawa; Mengfei Wang; Masato Kobayashi; Tetsuya Taketsugu; Yasuchika Hasegawa

doi:10.1002/anie.202405584

Chiral Tetrakis Eu(III) Complexes with Ammonium Cations for Improved Circularly Polarized Luminescence

Angew Chem Int Ed Engl. 2024 May 26:e202405584. doi: 10.1002/anie.202405584. Online ahead of print.

Authors

Makoto Tsurui¹, Ryohei Takizawa¹, Yuichi Kitagawa², Mengfei Wang³, Masato Kobayashi⁴, Tetsuya Taketsugu⁴, Yasuchika Hasegawa⁵

Affiliations

¹ Hokkaido University, Graduate School of Chemical Sciences and Engineering, JAPAN.
² Hokkaido University, Faculty of Engineering, JAPAN.
³ Hokkaido University, Institute for Chemical Reaction Design and Discovery, JAPAN.
⁴ Hokkaido University, Faculty of Science, JAPAN.
⁵ Hokkaido University, Faculty of Engineering, Kita-13, Nishi-8, Kita-ku, 060-8628, Sapporo, JAPAN.

PMID: 38797714
DOI: 10.1002/anie.202405584

Abstract

Large dissymmetry factor of the circularly polarized luminescence (gCPL) was observed in ligand and coordination tuned chiral tetrakis europium (Eu(III)) complexes with ammonium cations. The gCPL value was estimated to be -1.54, which is the largest among chiral luminescent molecules. Through photophysical measurements, single crystal X-ray structural analyses and quantum chemical calculations, changes in the geometric and electronic structures were observed for a series of chiral tetrakis Eu(III) complexes which enhanced the gCPL value. The emission quantum yield and photosensitized energy transfer efficiencies of chiral Eu(III) complexes with ammonium cations were also larger than that with previous Cs+. Based on the systematic modifications and analyses for chiral tetrakis Eu(III) complex, effect of the ammonium cation on enhanced CPL brightness is reported.

Keywords: Circularly Polarized Luminescence; chirality; europium; lanthanides.