Self-assembly And Host-guest Interaction Of Terpyridine-derived Fluorescent Molecules

cucurbit[n]urils(Q[n]s or CB[n]s) is a macrocyclic host which plays a key role in supramolecular chemistry in recent decades.In particular,Q[7]and Q[8]showing various host-guest interaction modes in host-guest chemistry attributed to the different cavity sizes.On the basis of published literatures and our laboratory studies,three series of terpyridine-derived fluorescent molecules were designed and synthesized,and their host-guest interactions with Q[7]and Q[8]as well as anion recognitions were studied in the present thesis.1.An AIE amphiphilic monomer(NI-TPy~+Br~–) containing Naphthalimide(NI),terpyridine skeleton and styrylpyridine cation(TPy~+)was synthesized.An unprecedented tunable hydrophobic effect in self-assembly of a small cationic organic fluorophore(NI-TPy~+)-based with aggregation-induced emission(AIE)property was realized in aqueous solution.The amplification of hydrophobicity was found to be significantly dependent upon the increasing aggregates of NI-TPy~+,which enabled the study of the hydrophobic binding of chaotropic anions with the Hofmeister series.2.Four kinds of pyridine-derived cation guest molecules(TPYA-1?TPYA-2?TPYA-3?TPYA-4)with different length alkyl chains were synthesized.The host-guest interaction between TPYA-1?TPYA-2?TPYA-3?TPYA-4 and Q[7]?Q[8]was investigated by UV-vis and fluorescence spectroscopy,nuclear magnetic resonance spectroscopy,respectively.It was found that in neutral aqueous solution,1:2host-guest interaction of Q[8]with TPYA-1 was formed,while 1:1 complex of Q[8]with TPYA-2?TPYA-3?TPYA-4 was formed.In particular,U-shaped conformation was formed attributed to TPYA-4 with longer alkyl chain.In addition,1:1 complex of Q[7]with all the guest was also confirmed.3.Four kinds of pyridine cationic guest molecules(TPYB-1?TPYB-2?TPYB-3?TPYB-4)with different length of carboxylic acid alkyl chain were synthesized,and their host-guest interactions with Q[7]and Q[8]were investigated by UV-vis and fluorescence spectroscopy and nuclear magnetic resonance spectroscopy under acidic and alkaline conditions.The results showed that:under acidic conditions,the host-guest complex of Q[8]with TPYB-1,TPYB-2 and TPYB-3 was found to be 1:2,and U-shaped conformation with 1:1 complex fashions was found in TPYB-4 guest.It was found that 1:1 complex of Q[7]with all the guest was formed.