Fluorescent Supramolecular Host-Guest Complexes Constructed By Conjugated Guanidinothiophene Pillar[5]arenes And Their Applications In Ion Detection

Fluorescent supramolecular host-guest complexes based on supramolecular macrocyclic host-guest recognition and assembly have potential applications in chemistry and material science because of their unique photophysical properties,stimulus response and dynamic reversibility.As a rising star of the classical supramolecular macrocycle,pillararenes have the advantages of unique host-guest properties and facile derivatization,and are considered to be one of the best hosts for constructing new fluorescent supramolecular host-guest complexes.Therefore,the synthesis of novel pillararenes and the construction of fluorescent supramolecular host-guest complexes based on pillararenes are of great significance to promote the advance of supramolecular chemistry and expand applications of fluorescent supramolecular materials.In this thesis,conjugated mono/diguanidinothiophene pillar[5]arenes host H1 and H2and bibranched guest G containing cyano-triazole complex site were synthesized,and supramolecular host-guest complexes G（?）H1 and G（?）H2 with assembly-induced emission enhancement based on H1 and H2 with G were constructed.The fluorescent supramolecular host-guest complexes G（?）H1 and G（?）H2 not only act as fluorescent chemosensors for the detection of heavy metal ions but also toxic anions.Moreover,the G（?）H1 showed selective performance with lowest detection limits of 0.9×10^-5 M and0.49×10^-5 M for Cu²⁺and OH^-respectively,the G（?）H2 showed lowest detection limits of1.49×10^-5 M,4.14×10^-5 M and 0.86×10^-5 M for Cu²⁺,Fe³⁺and HSO₄^-,respectively.The projects in this thesis have certain reference value for derivatization and functionalization of guanidinothiophene pillar[n]arenes,and pave a new approach to develop novel fluorescent supramolecular functional materials with stimulus response.In this thesis,we carried out the design and synthesis of hosts and guest,the constructions and applications of fluorescent supramolecular host-guest complexes.It mainly includes the following aspects:1.Conjugated mono/diguanidinothiophene pillar[5]arenes host H1 and H2 were synthesized by several coupling reactions,and yields were as high as 88%.2.The fluorogenic signaling pyrene and cyano-triazole were connected to the core structure of（2,6-Dimethyl-4H-pyran-4-ylidene）by covalent bond via click reaction to synthesize a bibranched guest G.The host-guest behavior and photophysical properties of host H1 and H2 with guest G were investigated,respectively.3.Fluorescent supramolecular host-guest complexes G（?）H1 and G（?）H2 based on H1and H2 with G were constructed respectively,and applied to the detection of heavy metal ions and toxic anions.Moreover,the G（?）H1 showed specific and selective performances with lowest detection limits of 0.9×10^-5 M and 0.49×10^-5 M for Cu²⁺and OH^-respectively,G（?）H2 showed lowest detection limits of 1.49×10^-5 M,4.14×10^-5 M and 0.86×10^-5 M for Cu²⁺,Fe³⁺and HSO₄^-,respectively.The projects in this thesis are significant for derivatization and functionalization of guanidinothiophene pillar[n]arenes,and pave a new approach to develop novel fluorescent supramolecular functional materials with double stimulus response.