Evaluation of circularly polarized luminescence in a chiral lanthanide ensemble. Issue 1 (3rd October 2017)

• Record Type: Journal Article
• Authors: Okayasu, Yoshinori; Yuasa, Junpei
• Is Part Of: Molecular Systems Design and Engineering. Volume 3:Issue 1(2018)
• Page Start: 66
• Page End: 72
• Publication Date: 2017-10-03
• Subjects: Chemistry -- Molecular aspects -- Periodicals; Chemical engineering -- Molecular aspects -- Periodicals; Nanotechnology -- Periodicals; 620.5
• DOI: 10.1039/c7me00082k
• Languages: English
• ISSNs: 2058-9689

Abstract

Abstract : The circularly polarized luminescence of a chiral europium(iii ) (Eu III ) complex species has been successfully evaluated in an ensemble system. Abstract : This work demonstrates a methodology for the evaluation of circularly polarized luminescence of a chiral europium(iii ) (Eu III ) complex species in an ensemble system. The chiral Eu III complex species consists of chiral bis(oxazolinyl)pyridine [( R )- or ( S )-iPr-Pybox] and β-diketonate ligands with a pendant nitro group (DK-NO2 ). The pendant NO2 group in [iPr-Pybox](Eu III )(DK-NO2 )3 (monometallic Eu III species) coordinates to the Eu III center of another Eu III complex, giving rise to the generation of a chiral Eu III ensemble consisting of mono-, di-, and the other oligomeric Eu III species, {[iPr-Pybox](Eu III )(DK-NO2 )3 } n . The luminescence dissymmetry factors ( g lum ) of the chiral Eu III ensemble have been successfully determined by using a commercially available fluorescence spectrophotometer attached with a rotatable λ /4 filter and a fixed linearly polarized plate. This study suggests that the chiral Eu III ensemble in solution displays a large circularly polarized luminescence (| g lum | = 0.19) as compared to that of a reference monometallic complex [iPr-Pybox](Eu III )(DK-CN)3 (| g lum | = 0.11–13). The larger g lum is primarily attributed to the contribution of the dimetallic Eu III species exhibiting a high degree of circular polarization in luminescence ( g lum2 = 0.27) in the ensemble. Conversely, a large linearly polarized component was observed in luminescence from the chiral Eu III ensemble in the solid state (KBr pellet).