Despite the desirability of organic isomer recognition and separation, current strategies are expensive and complicated. Here, a simple strategy for simultaneously recognizing and separating organic isomers using pillararene-based charge-transfer cocrystals through the cooperative control of pore-inside and pore-outside intermolecular interactions is presented. This strategy is illustrated using 1-bromobutane (1-BBU), which is often produced as an isomeric mixture with 2-bromobutane (2-BBU). According to its structure, perethylated pillar[5]arene (EtP5) and 3,5-dinitrobenzonitrile (DNB) are strategically chosen as a donor and an acceptor. As a result, their cocrystal exhibited stronger pore-inside interactions and much weaker pore-outside interactions with 1-BBU than with 2-BBU. Consequently, nearly 100% 1-BBU selectivity is achieved in two-component mixtures, even in those containing trace 1-BBU (1%), whereas free EtP5 only achieved 89.80% selectivity. The preference for linear bromoalkanes is retained in 1-bromopentane/3-bromopentane and 1-bromohexane/2-bromohexane mixtures, demonstrating the generality of this strategy. Selective adsorption of linear bromoalkanes induced a naked-eye-detectable color change from red to white. Moreover, the cocrystal are used over multiple cycles without losing selectivity.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.