Spectroscopic Determination of Binding Constants and Isomerization Behavior of Brooker’s Merocyanine Within Modified β-Cyclodextrins
Arts and Sciences
Host-guest complexation occurs when a guest molecule is held inside a host molecule through weak intermolecular forces, without actually forming bonds. β-cyclodextrin, a host molecule, has a variety of uses and can be used in pharmaceuticals; therefore, a fundamental understanding of how intermolecular forces affect complexation is significant. Binding constants of host-guest complexes of Brooker’s merocyanine and various modified β-cyclodextrins (2-hydroxypropyl-β-cyclodextrin, sulfated β-cyclodextrin, and methyl-β-cyclodextrin) were studied using fluorescence and UV-Vis spectroscopy to determine the strength of interaction between the host molecule and the most stable form of the guest molecule. By modifying the β-cyclodextrin, the effect of ionic interaction, hydrogen bonding, and steric hindrance were compared. It was determined that β-cyclodextrin modified with sulfate groups had a much lower binding constant than the other modified β-cyclodextrins, which could be due to a combination of ionic interactions and steric hindrance. The isomerization behavior of the guest molecule within the modified β-cyclodextrins can also be affected by various forces, specifically steric hindrance and hydrogen bonding. Depending on the desired properties of the host-guest complex, a particular binding strength and isomeric form of the guest molecule may be preferred. A comparison of these results to the theoretical models will lead to verification of the effect of these forces on binding and the isomerization behavior.
Hanson, Carly S., "Spectroscopic Determination of Binding Constants and Isomerization Behavior of Brooker’s Merocyanine Within Modified β-Cyclodextrins" (2015). Symposium on Undergraduate Research and Creative Expression (SOURCE). 442.