Pillar[5]arene-based diglycolamides for highly efficient separation of americium(III) and europium(III).

Pillar[5]arenes, as a new intriguing class of calixarene analogues, were functionalized with ten diglycolamide (DGA) arms on both sides (rims) of the pillar framework and evaluated for their extraction behaviour towards Am(III) and Eu(III). These novel extractants exhibit excellent separation and extraction efficiency, suggesting its significant potential for nuclear waste remediation. Laser induced fluorescence experiments disclosed strong complexation of the trivalent metal ions with the pillararene-DGA ligands.

Nonaggregational shape-persistent cyclo[6]aramide and its macrocyclic effect toward binding secondary ammonium salts in moderately polar media.

Simply by introducing steric side chains, the shape-persistent cyclo[6]aramides were found to exhibit nonaggregational behavior and strong association (3 × 10(4) M(-1)) ability in acetone for binding secondary ammonium salt. The complexation can be switched in an on-and-off fashion using AgPF6 and TBACl, contrasting sharply with their corresponding acyclic pentamer and demonstrating the macrocyclic effect.

Surface charge inversion of self-assembled monolayers by visible light irradiation: cargo loading and release by photoreactions.

In this study, we find that visible light can trigger both the loading and the release of N-alkyl substituted 4-picolinium on self-assembled monolayers (SAM). The latter process will result in surface-charge inversion of the SAM, which can be used for controlled release of molecules of interest.

Synthesis of crescent aromatic oligoamides with preorganized chelating groups and their extraction towards transition metal ions.

Three crescent aromatic oligoamides 1-3 with their backbones rigidified by intramolecular hydrogen bonds were designed and synthesized. The liquid-liquid extraction by these compounds has been investigated using UV-vis spectrometry towards Pb(2+) picrate and some transition metal picrates including Ag(+), Hg(2+), Cd(2+), Zn(2+), Cu(2+), Co(2+), Ni(2+) salts. The results revealed higher selectivity and efficiency towards Hg(2+) over other metal cations; pentameric ligand 1 with six oxygen donor atoms provided the highest extractability of 83.3%, while dimeric ligand 3 extracted almost exclusively Hg(2+). The stoichiometry of the extracted complex between ligand 1 and Hg(2+), and the extraction constant (logK(ex)) were determined in solvent extraction.