Binding Study of Monohydroxy Cucurbit[7]uril with Rhodamine B

Background: Cucurbit[7]uril (CB[7]) is the most important host among the reported cucurbit[n]urils family members, because it exhibited unique molecular recognition with exceptional applications. The binding affinity of functionalized CBs, especially mono hydroxylated CB[7] is important, because it will help to understand the difference in binding profile of functionalized CB[7] in comparison to that of the parent CB[7]. Materials and Methods: We have utilized Rhodamine B (RhB) to get encapsulated in monohydroxy CB[7] (CB[7]-OH) and measured the binding affinity of RhB in water. Results: The binding properties showed that the CB[7]-OH and RhB formed a 1:1 host-guest complex and the binding constant was found to be 3.75 × 104 M-1, which is slightly lower than the binding affinity of the parent molecule CB[7], which indicates that the binding behavior of CB[7]-OH not deviated much from the parent CB[7] molecule. Electrostatic Potential studies of these two molecules also supported these results. Conclusion: The binding studies of monohydroxy CB[7] (CB[7]-OH) successfully studied with RhB in water.