Remarkable Effects of External Magnetic Field on Circularly Polarized Luminescence of EuIII (hfa)3 with Phosphine Chirality

Chemphyschem. 2021 Sep 3;22(17):1728-1737. doi: 10.1002/cphc.202100280. Epub 2021 Jul 30.

Abstract

Herein, magnetic circularly polarized luminescence (CPL) (MCPL) spectroscopy was conducted to analyze an EuIII (hfa)3 complex with three chiral PIII -ligands. Resultantly, (R)-chirality luminophores with S-up orientation and (S)-chirality luminophores with N-up orientation were observed to possess symmetrical mirror image spectra, i. e., they were enantiomers. Similarly, the (R)-chirality luminophores with N-up orientation and the (S)-chirality luminophores with S-up orientation were also enantiomers. Contrarily, (R)-S-up and (S)-S-up were diastereomers and did not possess a mirror-image relationship. Likewise, (R)-N-up and (S)-N-up were diastereomers. The J-dependency of gMCPL and gCPL datasets suggested that the N-up/S-up external magnetic field, with the aid of chiral PIII -ligands, increased the gMCPL values by two- to sixteen-fold and modulated the gMCPL signs at J=1-4. Additionally, the origins of the nonideal mirror-symmetric CPL and MCPL spectral characteristics of EuIII (hfa)3 with three chiral PIII -ligands were discussed in terms of parity (space-inversion, P)-symmetry, time-reversal (T)-symmetry, and PT-symmetry laws.

Keywords: 4f-4f transitions; chirality; circularly polarized luminescence; europium; ligand effects.

Publication types

  • Research Support, Non-U.S. Gov't