Binding of neutral guests

Abstract

This chapter examines the binding of neutral guest molecules. Primarily, due to their uncharged nature, the interactions between neutral guests and host molecules are comparatively a lot weaker than the dominant electrostatic forces of ions. Instead, receptors designed to bind neutral molecules have to rely on hydrogen bonding, π–π interactions, Lewis acid interactions, and the hydrophobic effect to a much greater extent. Selectivity by dedicated host molecules is now dictated to an even greater extent by the fundamental principles of complementarity and preorganization. In addition, binding by 'physical incarceration/imprisonment' of neutral molecules within the cavities of larger host molecules now plays a much bigger and prominent role than that for ions. The chapter then considers how macroscopic crystalline solid host molecules, such as metal–organic frameworks (MOFs), can be exploited and engineered for binding of neutral guest molecules both in solution and in the gaseous phase.