Diazo reductive: a new approach to the synthesis of novel “upper rim” functionalized resorcin[4]arene Schiff-bases

Resorcin[4]arene Schiff base derivatives: Synthesis, characterization, and extraction studies

Novel 2,6-dihydroxyacetophenone[4]arene derivatives with an electron-withdrawing group at the ortho-position are developed. The 2,6-dihydroxyacetophenone[4]arene derivatives are condensed with benzylamine in chloroform to give the Schiff base derivatives of resorcin[4]arene. The acetyl group of the 2,6-dihydroxyacetophenone[4]arenes is condensed with primary amine groups to form imines. The multifunctional target molecules are purified and isolated in good yields. The Schiff base derivatives are characterized by elemental analysis, 1H and 13C nuclear magnetic resonance spectroscopy, infrared spectroscopy, and mass spectrometry. All the Schiff base compounds are successfully used for the extraction of toxic metals including Ni2+, Mn2+, Hg2+, Co2+, and Na+ using a liquid–liquid solvent extraction process. Among these tested metals, the percentage extraction of Hg2+ is the highest. As sodium dichromate has greater oxidative stability to transfer the HCr2O7− anion from an aqueous a protonated ligand solution, an anionic extraction study of dichromate is tested at various pH values.

A light controlled cavitand wall regulates guest binding

Here we report a cavitand with a photochemical switch as one of the container walls. The azo-arene switch undergoes photoisomerization when subjected to UV light producing a self-fulfilled cavitand. This process is thermally and photochemically reversible. The reported cavitand binds small molecules and these guests can be ejected from the cavitand through this photochemical process.