Relationship Between Structure and Coordination Strength of N and N,O-Hybrid Donor Ligands with Trivalent Lanthanides

Abstract

The details of UV spectroscopic titration and EXAFS experiments are compiled in this section. The pKa values for calculation of log  are compiled in Table S-1 and the example of the fitting results of MeTol-PTA are shown in Figure S-1. The pKa value of MeTol-PTA with two protons (MeTol-PTA-H 2 ) was difficult to estimate due to the low UV adsorption but the results of spectral fits were obtained in satisfactory quality with MeTol-PTA as shown in Figure S-1. Figures 5a and 5b are plotted using the data in Table S-2, S-3 and S-4. The EXAFS oscillations and theoretical fits are summarized in Figures S-2 and S-3.

Study on Phenanthroline Carboxamide for Lanthanide Separation: Influence of Amide Substituents

“…In the presence of an aromatic ring, there is a maximum around Pr−Sm, which is in agreement with Table 7. This maximum, as reported by Nakase et al, 16 can be explained by ion-size effects: the cation lies in a cavity induced by the N−N−O atoms of the phenanthroline, whose size is better suited for the bigger light Lns, hence the preference of all PTA and PTdA ligands toward the light Lns. To adapt to the different ionic radii, the amide oxygens need to slightly rotate, but this rotation is limited in the presence of the aryl ring, making the cavity less suitable for the biggest cations La/ Ce.…”

“…Both stoichiometries were found stable in the gas phase. Upon the addition of nitrate ions in the inner sphere, only the 1:2 complex has been studied, as previous studies reported slope analyses of 2 only in nitrate media 14 and a crystal structure with the 1:2:2 stoichiometry, 15,16 the third nitrate ion being in the outer sphere. Therefore, only the 1:2 results are reported in Table 3, showing the average distance of the closest atoms around Nd for different PTA ligands with two nitrate ions.…”

“…In this study, we chose to focus on phenanthroline carboxamide-based ligands because of their good extraction behavior as reported in the literature. Table lists some phenanthroline carboxamides that have already been studied. − The dicarboxamide ligands have mainly been studied for the separation of actinides from the lanthanides and not as a direct application for adjacent lanthanides separation, although some data on some or the whole Ln series are often provided. In all of these studies, either a rather flat trend all along the series for N -dialkyl ligands or a preference towards light Ln for N -alkyl, N -aryl was obtained, and separation factors between minor actinides and lanthanides could reach up to 2 orders of magnitude.…”

Complexation Studies of Eu(III) by a Novel Soft N and Hard O Donor Combined Ligand Including <i>N,N,N',N'</i>-Tetrakis(2-pyridylmethyl)-1,3-diaminopropane-2-amide Structure: UV-vis Titration, X-ray Crystallography, EXAFS Spectroscopy Analysis

“…Taking into consideration the single crystal structure, the first peak was assigned as the effect of N and O atoms in TPTNA, NO 3 -, or even MeOH and H 2 O molecular formed in the first coordination shell [16]. Furthermore, the shape of the first peak became unsymmetrical and shifted slightly to a higher position, indicating the different distances of Eu-N(TPTNA) and Eu-O(TPTNA) [17].…”

Impact of Coordination Modes of N‐Donor Ligands on Am(III)/Eu(III) Separation in Nuclear Waste Water Treatment – A DFT Study

“…[7a] Therefore, a class of mixed ligands (N, O-donor ligands) such as pyridine-6-carboxamide (BIZA), [8] N,N'-diethyl-N,N'-ditolyl-pyridine2,6-dicarboxamide (Et-Tol-PyDA). N,N'-diethyl-N,N'-ditolyl-2,9-diamide-1,10phenanthroline(Et-Tol-DAPhen), N,N'-diethyl-N,N'-ditolyl-2,2'-bipyridine-6,6'-dicarboxamide (Et-Tol-BPyDA), [9] N-methyl-N-tolyl-1,10-phenanthroline-2-carboxamide (MeTol-PTA) [10] and 6,6''-(2,2' : 6',2''-terpyridine)dicarboxylic acid diamides (TPDCA) [7] have been studied in the recent past. Though many derivatives based on these aforementioned ligands are prepared with varying coordination modes, some have a higher selectivity for actinides while others do not turn up to be good candidates.…”