Interlocking increases the persistence of N-heterocyclic carbenes in solution

Chem Commun (Camb). 2020 Apr 30;56(35):4773-4776. doi: 10.1039/d0cc01183e.

Abstract

In this study imidazolium and imidazolinium centers in precursor [2]rotaxanes were deprotonated to obtain interlocked molecules featuring stabilized N-heterocyclic carbene centers. The encircling macrocyclic components enhanced the persistence of the otherwise unstable imidazolidin-2-ylidenes in solution at 253 K for more than a week in the absence of air.