Open-cage fullerene with a stopper acts as a molecular vial for a single water molecule

Abstract

An open-cage fullerene derivative with three carbonyl groups on the rim of the orifice reacts with o-diaminobenzene reversibly to form a tetrahydrofuran moiety above the orifice. Water encapsulation and release experiments show that the tetrahydrofuran moiety acts as a stopper effectively blocking the orifice. The addition and removal of o-diaminobenzene serve as a chemically controlled switching process for the fullerene-based water container, which is suited for just one water molecule due to its moderate cavity size.