Study On The Interaction Of Cucurbiturils With Carbazole Derivatives And Sildenafil Citrate

Cucurbit[n]turils (n=5～8,10, denoted as CB[n]) have now being a new kinds of supramolecular hosts in the host-guest chemistry after crown ethers, calixarenes and cyclodextrins. They have attracted great attention owing to their unique structures and potential application in molecular recognition, molecular machine, molecular catalysis and drug carrier. In this thesis, the supramolecular interactions of cucurbiturils with carbazole derivatives and sildenafil citrate have been investigated.1. Ten carbazole derivatives were synthesized. The interactions of CB[n](n=7,8) with these synthetic guests have been investigated by using1H NMR, ESI-MS, UV-vis and molecular simulation method in the aqueous solution. The experiment results revealed that CB[n](n=7,8) can selectively interact with carbazole derivatives to form1:1inclusion complexes.2. The supramolecular interactions of6CMZ with CB[n](n=7,8) were investigated by’H NMR, ESI-MS, UV-vis and molecular simulation method in the aqueous solution. It was found that CB[7] and CB[8] can form a1:1inclusion complex with6CMZ resperictively. The1H NMR revealed that the addition of CB[7] and CB[8] could inhibit the H/D exchange of the C(2) proton in imidazole ring.3. The host-guest chemistry of systems containing Sildenafil Citrate (denoted as SCT) and cucurbit[n]uril (denoted as CB[n], n=7,8) was investigated by!H NMR, ESI-MS, IR, and UV-vis spectra. The experiment results revealed that the Sildenafil Citrate guest and CB[n](n=7,8) host could form a stable1:1(molar ratio) inclusion complex, in which the position of CB[n](n=7,8) was different because of the size of their cavity. The inclusion constant of Sildenafil Citrate with CB[7] and CB[8] was958L/mol and1530L/mol, respectively. The binding constant which located between102L/mol～103L/mol indicates that CB[7]and CB[8] could be used as a potential slow-released agent.