Octaphosphinoylated para-tert-butylcalix[8]arene as an extracting agent for uranyl ions in an acidic nitrate medium: study of the extracted uranyl calixarene compound

Theoretical assessment of calix[4]arene-N-β-ketoimine (n=1-4) derivatives: Conformational studies, optoelectronic, and sensing of Cu2+cation

Herein, we have investigated the key functions of the calix[4]arene, abbreviated as CX [1], and designed its several derivatives by substitution of the functional groups. Molecular geometry provides an intuitive understanding of the effect of functional groups on various physical properties. The addition of the N-β-ketoimine (n = 1-4) ligands has a direct effect on the stretching vibration of the H-bonding interaction. The results showed that all molecules possess absorption bands at 190 nm and in the range between 200 and 300 nm assigned to π-π* and n-π* transitions. HOMO-LUMO energy gap of the CX[4]-N-β-ketoimine, one with chemical hardness of 1.62 eV, has been found to be 3.24 eV calculated at B3LYP/6-31 + G(d) level of theory. This finding explains the good kinetic stability of this compound. The large values of electrophilicity make the current molecules as a good electrophilic species. The atom in molecule (AIM) and the reduced density gradient (RDG) analyses showed the type and the strength of the interactions taking place between Cu²⁺ and the β-ketoimine ligands.

Synthesis of para-linked azacalix[n]pyridine[n]pyrazines and their uranyl ion binding properties

Based on the fragment coupling strategy, the novel macrocycles, para-linked azacalix[n]pyridine[n]pyrazines (n = 2 and 4) with coexisting different heteroaromatics, were synthesized readily starting from 2,5-dibromopyrazine and 2,6-dibromopyridine.