Wading through the spectrum of wetness
The importance of the influence of the shape of concavities and the nature of those concavities to its solvation in water is oft neglected. The hydration of nanoscopic concavities can be influenced by the addition of functionality to the portal of such concavities. In this dissertation the formation of stable water clusters and stable, vacuous spaces within deep-cavity cavitands is described. Stable water clusters can be formed by the addition of negative charges to the portal of the cavity (as in exo-octa-acid), reinforcing the hydrogen bonding network of the bound water molecules. This makes water a better guest for the pocket of the deep-cavity cavitand, inhibiting the binding of guests by making the water cluster more energetically unfavourable to displace. On the hand, the addition of alkyl groups pointing inwards towards the portal (as in tetra-endo-ethyl octa-acid) induces a drying transition in the pocket, desolvating the pocket in solution. Alkyl groups are thus functionalities themselves, and not just backbones for functionality. The synthesis and properties of hosts that occupy the two extremes of hydration are herein described. The binding of alkanes to a predominantly vacuous host is also demonstrated. In addition, the synthesis, and preliminary studies of the properties of positively charged analogues of predominantly dry hosts are also described.