Abstract by Mariah Pay
Chemistry and Biochemistry
Cucurbituril Structure with Alkylammonium and Ion Cap.
Experiment and theory both suggest that alkylammonium cations bind to a pumpkin-like molecule cucurbituril (CB). We are studying the ability of a alkali metal ion cap to control the shape of the CB. As the ion blocks one side of the host, CB forces the alkyl chain out of its cavity. We use the Spartan modeling program with the Mereck Molcular Force Field to find likely structures for [metal+CB+alkylammonium]2+ complexes determining which versions have the alkylammonium tail facing outward or threaded through the center. Next, this information is input into an IMoS modeling package to predict distinct cases. Results show that with the metal ion present, short alkyl tails are still inside the CB, while longer tails are forced outside. Furthermore, the differences between the two cases are large enough that they should be experimentally measured. Ongoing work will be looking at the influences of chain length and of metal ion size on final structures.