Abstract by Mariah Pay
Chemistry and Biochemistry
Binding Prospects for Cucurbituril, Cucurbituril, and Decamethylcucurbituril With and Without Guests
Using the Spartan and Ion Mobility Spectrometry Suite (IMoS), we use molecular modeling to predict energy and sizes of proposed molecular structures for comparison with experiments on molecular size. Previously, we have observed that alkali metal cations bind to the portals of a hollow host molecule cucurbituril (CB5), thus forming a closed cavity suitable for trapping neutral guest molecules. The IMoS calculations are consistent with experiments that indicate that neutral guests such as methane bind inside the CB5 cavity. The larger CB6 host is not favored in forming closed molecular containers as the portal of CB6 is too large for all its oxygen atoms to bind the largest metal cations. Our research also included using ECCE with the NW Chem computational package to compute binding energies of CB5 and related host complexes toward metal ions and neutral guests. These studies show that CB5 with methane as an internal guest is lower in energy than binding methane outside the cavity. They also show that methane binds inside CB5 weaker than in the structurally-similar mc5 host. These computational studies are generally consistent with mass spectrometry experiments.