Determination of stability constants of some substituted 4-pyrazolone dyes containingo-methoxy,o-carboxy, ando-nitro groups with trivalent lanthanide ions

1987 ◽  
Vol 118 (10) ◽  
pp. 1101-1111 ◽  
Author(s):  
B. A. El-Shetary ◽  
S. L. Stefan ◽  
F. I. Zidan ◽  
S. B. El-Maraghy
Keyword(s):  
Stability Constants ◽  
Lanthanide Ions ◽  
Trivalent Lanthanide

scholarly journals Об экспериментальном определении параметров интенсивности 4f-4f-переходов по спектрам излучения соединений европия (III)

2022 ◽  
Vol 130 (1) ◽  
pp. 207
Author(s):  
Lucca Blois ◽  
Albano N. Carneiro Neto ◽  
Ricardo L. Longo ◽  
Israel F. Costa ◽  
Tiago B. Paolini ◽  
...  
Keyword(s):  
Unique Feature ◽  
Photon Counting ◽  
Emission Spectra ◽  
Lanthanide Ions ◽  
Quantum Yields ◽  
Correction Factors ◽  
Intensity Parameters ◽  
Trivalent Lanthanide ◽  
Integrated Intensity

Eu3+ complexes and specially β-diketonate compounds are well known and studied in several areas due to their luminescence properties, such as sensors and lightning devices. A unique feature of the Eu3+ ion is the experimental determination of the 4f-4f intensity parameters Ωλ directly from the emission spectrum. The equations for determining Ωλ from the emission spectra are different for the detection of emitted power compared to modern equipment that detects photons per second. It is shown that the differences between Ωλ determined by misusing the equations are sizable for Ω4 (ca. 15.5%) for several Eu3+β-diketonate complexes and leads to differences of ca. 5% in the intrinsic quantum yields Q_Ln^Ln. Due to the unique features of trivalent lanthanide ions, such as the shielding of 4f-electrons, which lead to small covalency and crystal field effects, a linear correlation was observed between Ωλ obtained using the emitted power and photon counting equations. We stress that care should be exercised with the type of detection should be taken and provide the correction factors for the intensity parameters. In addition, we suggest that the integrated intensity (proportional to the areas of the emission band) and the centroid (or barycenter) of the transition for obtaining Ωλ should be determined in the properly Jacobian-transformed spectrum in wavenumbers (or energy). Due to the small widths of the emission bands of typical 4f-4f transitions, the areas and centroids of the bands do not depend on the transformation within the experimental uncertainties. These assessments are relevant because they validate previously determined Ωλ without the proper spectral transformation.

Determination of stability constants for complexes from catalytic linear scan voltammetric currents

1998 ◽  
Vol 95 (5) ◽  
pp. 1091-1100 ◽  
Author(s):  
J. L. Muñiz Alvarez ◽  
J. A. García Calzón ◽  
J. M. López Fonseca
Keyword(s):  
Stability Constants

Bond-length distributions for ions bonded to oxygen: Results for the lanthanides and actinides and discussion of the f-block contraction

2017 ◽  
Author(s):  
Olivier Charles Gagné
Keyword(s):  
Bond Length ◽  
Coordination Number ◽  
Lanthanide Ions ◽  
Lanthanide Contraction ◽  
Trivalent Lanthanide ◽  
Actinide Ions

Bond-length distributions have been examined for eighty-four configurations of the lanthanide ions and twenty-two configurations of the actinide ions bonded to oxygen. The lanthanide contraction for the trivalent lanthanide ions bonded to O<sup>2-</sup> is shown to vary as a function of coordination number and to diminish in scale with increasing coordination number.

scholarly journals Deep Learning Insights into Lanthanides Complexation Chemistry

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3237
Author(s):  
Artem A. Mitrofanov ◽  
Petr I. Matveev ◽  
Kristina V. Yakubova ◽  
Alexandru Korotcov ◽  
Boris Sattarov ◽  
...  
Keyword(s):  
Deep Learning ◽  
Stability Constants ◽  
Black Box ◽  
Lanthanide Ions ◽  
Structure Property ◽  
Target Property ◽  
Mutual Location ◽  
Molecule Structure ◽  
Complexation Chemistry ◽  
Main Influence

Modern structure–property models are widely used in chemistry; however, in many cases, they are still a kind of a “black box” where there is no clear path from molecule structure to target property. Here we present an example of deep learning usage not only to build a model but also to determine key structural fragments of ligands influencing metal complexation. We have a series of chemically similar lanthanide ions, and we have collected data on complexes’ stability, built models, predicting stability constants and decoded the models to obtain key fragments responsible for complexation efficiency. The results are in good correlation with the experimental ones, as well as modern theories of complexation. It was shown that the main influence on the constants had a mutual location of the binding centers.

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