Design,Synthesis And Application Of Cucurbit[5]uril-based Self-assembly Materials

Cucurbit[n]urilis(Q[n]s)are a kind of relative new family of macrocyclic compounds after crown ethers,cyclodextrins and calixarenes in the field of supramolecular chemistry.Their rigid hydrohyphoibic cavities,electronegative portals lined up with carbonyl groups and electropositive outer surface have provides various research interests for the scienties of the filed of Q[n]s-based chemistry and also make them the promising materials in the application to various area,for example,molecular recognition,molecular switch,environmental protection,drug delivery and so on.Recently,with the development of Q[n]s-based chemistry,the construction of suopramolecular assemblies based on the outer-surface interactions of Q[n]s has becaome a hot topic in this area.Upon the introduction of the thirf species into the systems of Q[n] and metal ions,thse third species could not only facilitate the direct coordination of Q[n]s with metal ions but also function as structure-directing agents to generate multidimensional and multi-level supramolecular assemblies via the noncovalent ineractiosn between them and the outer surfaces of Q[n]s.Compared with common carboxylate ligands,sulfonate ligands have more diverse coordination models because the oxygen atom on the sulfonate groups could bind to metal ions from different directions and tend to serve as bridging ligands.Therefore,sulfonate ligands prefer to froming high-dimensional framworks when they coordinate with metal ions.Meanwhile,sulfonate groups are more likely to form multiple hyfrogen bonds because all of the three oxygen atoms on the sulfonate groups could functions as good acceptor in various directions.On the other hand,Q[5] is the smallest member in Q[n]s family and possess the highest density of carbonyl groups,which hence endow Q[5] with the strongest coordination ability for metal ions.Based on above considerations,in this thesis,three different sodium naphthalene disulfonate(Na2NDS)were employed as the structure-directing agents to react with Q[5] and various metal ions and 22 novel supramolecular assemblies(1 – 22)were successfully obtained.The introduction of 1,5-NDS2-,2,6-NDS2-and 2,7-NDS2-give 11,3 and 8 differnet supramolecular assemblies,respectively.In these complexes,only the Q[5] in the assembly 1 did not coordinate to any metal ions because no any extra metal ions were added during the process of synthesis,while all the Q[5] molecules in other assemblies coordinated directly to metal ions.In the structure of assemblies 2and 13,the binding of Q[5] to Na+/Ca2+ both gave Q[5]-based “molecular bowls”;in assemblies 3 – 7,the coordination between Q[5] and K+/Rb+/Cs+/Ba2+/Sr2+ all generated Q[5]-based “molecular capsules”;the connection of Q[5]s and Ca2+/Mg2+/Co2+/Ni2+/Zn2+ in assemblies 8 and 18 – 21 formed simple coordination compounds;while in the structure eof 12,14 – 17 and 22,the coordination between Q[5] and Na+/Ba2+/K+/Rb+/Ca2+/Cd2+ all constructed Q[5]-based one-dimensional coordination polymers.As for the introduced sulfonate ligands,they could serve as the couteranions to maintain the charge balance and function as the structure-directing agent to facilitate the formation of Q[5]-based supramolecular assemblies via the noncavalent interactions between them and the outer surface of Q[n]s.Furthermore,the sulfonate ligands could also bind to the metal ion to connect the Q[n]-based coordination complexes in some assemblies.In addition,the adsorption of five dye molecules by using 2,9,12,13,and 15 was investigated,and the results showed that 2 pairs of crystal violet had good adsorption for crystal violet.