In:
ChemPlusChem, Wiley, Vol. 85, No. 2 ( 2020-02), p. 294-300
Abstract:
Ligands based on 2,2’‐bipyridine and valinamide moieties induce circularly polarized luminescence in their europium complexes. Both the R and S enantiomers of the complexes were successfully obtained. Single‐crystal X‐ray analysis of the racemic crystal confirmed that the ligand is coordinated to the europium ion in a tetradentate fashion. The π‐electronic system of the ligand is co‐planar with the valinamide moiety, and acts as an efficient photoantenna to sensitize europium luminescence by UV excitation. The luminescence quantum yield (QY) of europium in the valinamide‐containing complex was 44 % in acetonitrile. The g lum value to evaluate the circularly polarized luminescence was relatively high at |0.13| estimated from their magnetic dipole transitions around 593 nm. For comparison, we prepared hexadentate europium complexes in the S ‐ and R ‐forms derived from two bipyridine moieties linked by ethylenediamines. The determined QYs were 18 % ( S ) and 16 % ( R ), and the g lum value |0.12| for the hexadentate complexes. The photophysical properties of the gadolinium complexes of the ligands were also evaluated.
Type of Medium:
Online Resource
ISSN:
2192-6506
,
2192-6506
DOI:
10.1002/cplu.201900692
Language:
English
Publisher:
Wiley
Publication Date:
2020
detail.hit.zdb_id:
2646595-4
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