Study On The Interaction Of Cucurbiturils With Viologen Derivatives And Buflomedil

Nowadays supramolecular chemistry has become one of the most interesting fields of chemical research, because of their potential applications in many aeras, including catalysis, separation of molecules or ions, environmental sciences and life sciences. Cucurbit[n]turils (n=5～8,10, denoted as CB[n]) and their homologues whose shape resembles a pumpkin have been greatly exploited as supramolecular hosts in the host-guest chemistry, environmental chemistry, materials chemistry, nano-chemistry and many other areas. In this thesis, the supramolecular interactions of cucurbiturils with viologen derivatives and buflomedil have been investigated.1. The viologen derivatives (denoted as C12MV, C7MV, C4MV and C2MV) were synthesized. The interactions of cucurbit[7,8]uril with these synthetic guests have been investigated by using 1H NMR, ESI-MS and UV-vis spectra. The experimental results revealed that CB[7] can interact with C12MV to form a 2:1 inclusion complex, while CB[8] and C12MV can form a very stable 1:1 inclusion complex. It was found that the electron-rich guests of HN can form a 1:1:1 inclusion complexe with C12MV, C7MV, C4MV and C2MV in the cavity of CB[8], respectively. In case of C12MV and C7MV, the different binding model was formed when HN or CB[8] is added first. Wheras, C4MV and C2MV can form the same 1:1:1 inclusion complex with HN and CB[8] no matter HN or CB[8] is added first. The selected binding ofβ-cyclodextrin (denoted asβ-CD) and CB[8](or CB[7]) with C12MV has also been studied. The CB[7] can form a 1:1:1 inclusion complex withβ-CD and C12MV. Wheras, CB[8] can releaseβ-CD from C12MV to form a U-shaped inclusion complex with C12MV.2. The host-guest chemistry of systems containing buflomedil(denoted as DLDE) and cucurbit[6,7,8]uril was investigated by 1H NMR, ESI-MS, IR and UV-vis spectra. The experiment results revealed that the size of the cavity of the CB[n] played an important role in the interaction between the host and the guest. Buflomedil could form a stable 1:1 inclusion complex with CB[7] and CB[8], whereas the interaction of Buflomedil with CB[6] was very weak. The inclusion constant of buflomedil with CB[7] and CB[8] is 1.43×103L/mol and 3.76×102 L/mol, respectively. The binding constant which was located between 102～103 L/mol indicate that CB[7] and CB[8] could be used as a potential slow-released agent.