The accurate dissection of binding energies into their microscopic components is challenging, especially in solution. Here we study the binding of noble gases (He–Xe) with the macrocyclic receptor cucurbit[5]uril in water by displacement of methane and ethane as ¹H NMR probes. We dissect the hydration free energies of the noble gases into an attractive dispersive component and a repulsive one for formation of a cavity in water. This allows us to identify the contributions to host–guest binding and to conclude that the binding process is driven by differential cavitation energies rather than dispersion interactions. The free energy required to create a cavity to accept the noble gas inside the cucurbit[5]uril is much lower than that to create a similarly sized cavity in bulk water. The recovery of the latter cavitation energy drives the overall process, which has implications for the refinement of gas-storage materials and the understanding of biological receptors.

将结合能准确地分解成它们的微观成分是有挑战性的，尤其是在溶液中。在这里，我们通过置换甲烷和乙烷为^1来研究水中稀有气体（He–Xe）与大环受体葫芦[5]尿素的结合1 H NMR探针。我们将稀有气体的水合自由能分解为一种有吸引力的分散成分和一种排斥性成分，以在水中形成空腔。这使我们能够确定对主客体结合的贡献，并得出结论，结合过程是由不同的空化能量而不是分散相互作用驱动的。建立一个空腔以容纳葫芦[5]内的稀有气体所需的自由能比在散装水中建立一个类似大小的空腔所需的自由能低得多。后一种空化能量的回收驱动了整个过程，这对气体存储材料的精炼和对生物受体的理解具有重要意义。