Host–Guest Inclusion Complexes

Abstract

Host–guest inclusion complexation represents the simplest example of a supramolecular process, in which a smaller “guest” molecule is included within the internal cavity of a larger, hollow “host” molecule. The formation of a host–guest inclusion complex in a solution can result in significant changes to the physical and chemical properties of the guest, including solubility, reactivity, stability and spectroscopic properties. In this chapter, some fundamental aspects of the formation of host–guest inclusion complexes in solution are described, including the mechanisms, driving forces and thermodynamics of the process, as well as common types of host molecules and materials, in the context of the applications of host–guest complexation to the prevention of corrosion and biofouling. Some specific representative examples of the use of host–guest complexes in corrosion and biofouling prevention are also discussed to illustrate these ideas, with a focus on cyclodextrins, cucurbiturils and calixarenes as molecular hosts.