Functional Naphthalimides:Synthesis,self-assembly And Recognition Properties

With the development of supramolecular chemistry,host-guest chemistry and self-assembly systems has been well-known by more and more scientists.Naphthalimide(NI)derivatives have been widely used to real life,because of its unique photophysical properties.Due to their strong electron-accepting ability and high fluorescence quantum yield,naphthalimides have attracted wide attention in the scientific community.Naphthalimides with aggregation-induced emission(AIE)have created a new class of AIE active materials that have great potential value for solving various practical applications in the aggregation state.Based on the naphthalimide-induced aggregation-induced emission after being reported for the first time,its synthetic route is easy and has potential application value.For many years,researchers have been exploring and studying the aggregating properties of naphthalimide compounds.Through the information in the existing literature,many research teams have invested a lot of energy to expand the application of naphthalimide light-emitting materials.Including biosensors,chemical sensors and self-assembly research and other fields have a good application value.In addition,it also explores applications in organic light-emitting diodes,stimulus-responsive materials,in vitro and in vivo imaging of cells,and biomolecules.Due to its good biocompatibility,light stability and aggregation-induced luminescence properties,naphthalimides are expected to be used for long-term bioimaging and cell tracking applications.In addition to the examples discussed,there are a number of reported naphthalimide derivatives that exhibit AIE features and may extend to many unknown applications.We are eagerly awaiting the discovery and development of these potentially surprising naphthalimide derivatives.In the first part: Hg2+ is one of the threatening heavy metal ions.It is very important to find a rapid and simple method to detect Hg2+.In this work,we designed and synthesized a simple chemical sensor Z(N,N-bis(1,8-naphthalenedicarboxylate)histidine sodium salt with high selectivity and high sensitivity to Hg2+.We designed and synthesized naphthalimide derivatives containing metal binding sites using histidine and 1,8-naphthalene anhydride for the identification and detection of mercury ions in water.The carboxyl and imidazole moieties in sensor Z can act as hydrophilic groups as well as Hg2+ binding sites,while the naphthalimide moiety serves as a fluorescent signal reporter group.Interestingly,sensor Z has good solubility in water and can show high selectivity and high sensitivity detection recognition of Hg2+ in water.Other coexisting competing metal ions(Fe3+,Ag+,Ca2+,Cu2+,Co2+,Ni2+,Cd2+,Pb2+,Zn2+,Cr3+,and Mg2+)did not interfere with the identification process.The detection limit of sensor Z to Hg2+ is 1.785×10-7 M,which shows a highly sensitive detection of Hg2+.In addition,sensor Z can undergo recycling.In the part two,we successfully developed a simple and efficient approach to endow the controllable multi-stimuli-responsive property for the supramolecular polymer was successfully developed by rationally introducing iodine into a novel naphthalimide-functionalized pillar[5]arene-based supramolecular polymer(PNA?GBP).Interestingly,by introducing iodine into the supramolecular polymer PNA?GBP,the iodine could not only control the optical properties and self-assembly states of PNA?GBP via electronic donor-acceptor effect but also control the molecular recognition properties by competitive redox reaction.We studied the self-assembly properties of the host(PNA)and the guest(GBP),founded that the host-guest self-assembled into micrometer solid spheres.When we added I2 into the supramolecular gel PNA?GBP,the microspheres were found been destroyed and the fluorescence quenched.Therefore,we made the supramolecular gel PNA?GBP·I2 without fluorescence,and conducted an ion response experiment.It was found that the supramolecular gel PNA?GBP·I2 could selectively fluorescent ?turn-on? detection of CN-,Hg2+,and L-Cys with high sensitivity not only in supramolecular polymer gels but also in DMSO-H2 O binary solution and in living cells.Benefiting from these excellent multi-responsive properties,the supramolecular polymer PNA?GBP·I2 can be used as a new intelligent material for selective detection of CN-,Hg2+ and L-Cys.