Isothermal calorimetry (ITC) was used to determine the binding free energy, enthalpy, and entropy of binding for the 18 binding reactions defined by our nine hosts and two guests. The same experimental conditions were used throughout, except that the concentrations of the reactants were adjusted individually to reach C values in a suitable range . A low ionic strength buffer (25 mM) was used to reduce the complexity of the overall systems for computational chemists, particularly as high ionic concentrations can significantly alter binding affinities, especially for charged systems . The compiled affinity data for all host-guest complexes are shown in Table . All of the fitted stoichiometries (N) are in the range 0.70 -1.18. Further experimental details (e.g., sample concentrations and enthalpograms) are available in the Supporting Information.