A novel and versatile precursor for the synthesis of highly preorganized tetradentate ligands based on phenanthroline and their binding properties towards lanthanides(III) ions

A step forward in unraveling the lanthanide discrimination puzzle: structure–selectivity relationship based on phenanthroline diimide ligands towards europium and terbium detection in water

“…1b, Phen-2DIBA features well-defined absorption and emission peaks, which are typical characteristics originating from the stiff ligand architecture. 42,47,48,52 All three subpeaks from Phen-2DIBA were ligand-originated, as evidenced by excitation spectra monitored at corresponding emissions (Fig. S6a, ESI†).…”

“…For Phen-2DIBA and Phen-2DIBA-re , the coordination of metal cations resulted mainly in the shifting of CO (carbonyl groups) and CN (phenanthroline) stretching peaks, confirming the ONNO binding nature for Phen-2DIBA and Phen-2DIBA-re . 47,48,52,58 From previous discussions, one could expect smaller Lns( iii ) binding constants for Phen-2DIBA-re with respect to Phen-2DIBA even though the attempt to calculate the binding constant for Phen-2DIBA-re failed because of the limited solubility in single-component aqueous media (Fig. S5 and associated solubility discussions, ESI†).…”

A Simple yet Efficient Hydrophilic Phenanthroline-Based Ligand for Selective Am(III) Separation under High Acidity

“…The dibutyric acid functionalized phenanthroline diimide ligand ( Figure 1 a, hereafter referred as Phen-2DIBA ) was synthesized following our previous report. 44 Briefly, the N -hydroxysuccinimide activated phenanthroline dicarboxylic precursor was mixed with 4-aminobutyric acid in dimethyl sulfoxide (DMSO) at room temperature. A catalytic amount of triethylamine was added, and then the mixture was stirred overnight before pouring into water to quench the reaction.…”

“…Further increasing the metal ions resulted in the downfield shifting of the aromatic peaks (most obvious for the peak at around 8.5 ppm), which has been frequently reported in the literature and could be ascribed to the metal coordination reducing the electron densities of the ligand. 7 , 17 , 25 , 44 , 47 , 48 After 5 equiv of Lu(III) was added, well-defined peaks corresponding to 1:1 species of Phen-2DIBA /Lu(III) dominated in the solution. A similar phenomenon was observed for the alkyl chain peak at around 3.1 ppm ( Figure S16 , corresponding to proton no.…”

“…The coordination modes of Phen-2DIBA with Eu(III) were elucidated by IR spectra and single-crystal X-ray diffraction. The characteristic IR peaks of Phen-2DIBA were definitively assigned according to literature reports 7,17,27,44 and by comparison with the IR spectra of Phen-2DIC4 (Figure S23). As given in Figure 4a and Figure S20, after coordinating with Eu(III) ions, the C� O (imide) peak at 1650 cm −1 shifted to 1636 cm −1 while the C�N peak (phenanthroline) at 1549 cm −1 shifted to 1570 cm −1 , which was well consistent with that observed for hydrophilic DS-Ph-DAPhen (Full IR spectra are given in Figure S24; note that the peak at around 1380 cm −1 was from nitrate ion 49 ).…”