Ionization of Cucurbiturils as a Pathway to More Stable Host-Guest Complexes

TL;DR

This paper explores how ionizing cucurbiturils enhances their ability to form more stable complexes with C60 fullerene, using density functional theory to analyze the electronic interactions involved.

Contribution

It introduces the concept of ionized cucurbiturils and demonstrates their improved binding stability with C60 fullerene through computational methods.

Findings

Ionization of cucurbiturils increases binding stability with C60.

Electron density polarization in C60 enhances host-guest interactions.

Ionized cucurbiturils form more stable complexes than neutral ones.

Abstract

Cucurbiturils are particularly interesting to chemists, because these macrocyclic molecules are suitable hosts for an array of neutral and cationic species. It is believed that the host-guest binding originated from hydrophobic interactions and ion-dipole interactions in the case of cationic guests. The fact that an elementary unit of cucurbiturils consists of two fused imidazole rings, which ionize readily, has remained largely unnoticed up to now. This work reports ionized cucurbiturils and their binding to C60 fullerene using versatile electronic-precision description. The methodology is based on density functional theory. We assert that cationization of cucurbiturils fosters C60-cucurbituril binding due to polarization of electron density in C60. Therefore, more stable host-guest complexes can be derived.