Study on preparation of pillararene cocrystals by liquid-assisted grinding

Abstract

Liquid-assisted grinding (LAG) has received wide attention in chemical synthesis field. Here, we reported that LAG provides a smart strategy to build macrocyclic cocrystal (MCC), achieving quick modification. The macrocyclic cocrystal has been assembled by electronegative permethylated pillar[5]arenes (EtP5) and electropositive ligands. We select three ligands with strong electron-deficient groups for cocrystal preparation with EtP5 by LAG and judge whether the grinding products are cocrystals by color change, Infrared (IR), Ultraviolet-visible (UV-vis) absorption, and X-ray diffraction (XRD). We demonstrated that the same structure as solvent cocrystal can be obtained by LAG. We obtained the single crystal structure of the EtP5 cocrystal with the promising ligand, confirming the formation of cocrystals and the reliability of the liquid-assisted grinding method.