Click-derived Macrocycles For Molecular Recognition

Macrocyclic receptor is a good anion receptor and it also can increase the recognition ability of anions.However,in the previous studies,it was difficult to synthesize.Because of the click reaction has mild reaction conditions,good selectivity,and high yields,it was used to synthesize 1,2,3-triazole and its alkylation product triazolium has become a very good method for synthesizing macrocyclic compounds.In this dissertation,we used click reaction successfully synthesis a series of macrocyclic receptors with styrene,fluorene and naphthalene as fluorophores,and we studied its ablity to recognation RNA,chloride and fullerene in solution.The details are as follows:1.An anionic macrocyclic receptor 1 was synthesized using TPE as fluorophore,amide and triazole guanidine as recognition sites.The ability to recognize different anions and biomacromolecules was studied by UV and fluorescence techniques.The results showed that the receptor molecule 1 has better fluorescence enhancement recognition ability in RNA in pure aqueous solution and can be used for intracellular RNA imaging.2.A macrocyclic acceptor 2 containing pyrene fluorophore,triazolium,and amide hydrogen as the anion recognition sites was reported.In THF solvent,this receptor has a very good fluorescence enhancement effect on selective anions,especially chloride ions.¹H NMR titration and DFT calculations showed that the triazole ring（CH）⁺,amide NH,and benzene ring CH sites of the macrocyclic acceptor have a good hydrogen bonding effect with chloride ion.3.Two neutral macrocyclic acceptors 3 and 4 containing four triazole groups were synthesized with naphthalene and TPE as fluorophores.Receptor 3 showed characteristic fluorescence of naphthalene,and has a good fluorescence quenching effect on fullerene C60 in mixed solvents of toluene and THF:H₂O（3:7,v/v）.Compound 4 was found to have the best response for C60 when THF:H₂O was 3:7,while Compound 3 was the best in the pure organic phase.The use of DFT for receptor 3’s mechanism of action.