TY - JOUR

T1 - Seven Europium(III) Complexes in Solution - the Importance of Reporting Data When Investigating Luminescence Spectra and Electronic Structure

AU - Thomsen, Maria S.

AU - Nawrocki, Patrick R.

AU - Kofod, Nicolaj

AU - Sorensen, Thomas J.

PY - 2022

Y1 - 2022

N2 - Despite significant effort, the complexity of europium(III) luminescence in general-and sample composition in particular-has precluded the publication of standard spectra of specific complexes in aqueous solution. Further, low spectral resolution, weighted averages with contributions from several species, as well as poor reproduction hampers the use of literature data, with the note that high quality data from e. g. Bunzli, Latva, Carnall, Parker, Heller, Balzani and Sabatini is from the pre-electronic era. Here, luminescence spectra of Eu.DOTA, Eu.EDTA, Eu.DPA(1), Eu.DPA(2). Eu.DPA(3), Eu.DTPA and the Eu(III) aqua ion was determined in samples with known pH and conductivity. The ligand concentrations were varied in a buffered medium (MES) with a significant salt background. In this manner, full complexation could be ensured, while pH and ionic strength were monitored. The spectra corresponding to the complexes were extracted, and the electronic structure of the ground state F-7(J) manifold was investigated and contrasted to literature data. All spectroscopic data is made available and we suggest this becomes part of the standard procedure when investigating lanthanide(III) complexes.

AB - Despite significant effort, the complexity of europium(III) luminescence in general-and sample composition in particular-has precluded the publication of standard spectra of specific complexes in aqueous solution. Further, low spectral resolution, weighted averages with contributions from several species, as well as poor reproduction hampers the use of literature data, with the note that high quality data from e. g. Bunzli, Latva, Carnall, Parker, Heller, Balzani and Sabatini is from the pre-electronic era. Here, luminescence spectra of Eu.DOTA, Eu.EDTA, Eu.DPA(1), Eu.DPA(2). Eu.DPA(3), Eu.DTPA and the Eu(III) aqua ion was determined in samples with known pH and conductivity. The ligand concentrations were varied in a buffered medium (MES) with a significant salt background. In this manner, full complexation could be ensured, while pH and ionic strength were monitored. The spectra corresponding to the complexes were extracted, and the electronic structure of the ground state F-7(J) manifold was investigated and contrasted to literature data. All spectroscopic data is made available and we suggest this becomes part of the standard procedure when investigating lanthanide(III) complexes.

KW - Data Availability

KW - Electronic Structure

KW - Europium(III)

KW - f-elements

KW - Lanthanide Luminescence

KW - LANTHANIDE

KW - COORDINATION

KW - DYNAMICS

KW - IONS

KW - SOLVATION

KW - BINDING

KW - PROBES

KW - WATER

KW - EU3+

U2 - 10.1002/ejic.202200334

DO - 10.1002/ejic.202200334

M3 - Journal article

VL - 2022

JO - European Journal of Inorganic Chemistry

JF - European Journal of Inorganic Chemistry

SN - 1434-1948

IS - 27

M1 - e202200334

ER -