Design,synthesis And Sensing Ability Of Fluorescent Probes For Cyanides Based On Nucleophilic Aromatic Substitution Of Hydrogen

Cyanide ions widely exist in nature and organisms and play an important role in the fields of chemistry,medicine,biology and environment.However,the excessive existence of cyanide ions will bring harms of organisms and environmental pollution.Therefore,more and more attention has been paid to the development of chemical sensors for the specific and selective recognition of cyanide ions.Naphthalimide derivatives have the advantages of stable structure,bright color,easy synthesis and excellent photoelectric properties.Hence,it can be used as an excellent chromophore to identify anions in sensors design.The topic on the basis of existing literature,electron-withdrawing groups(e.g.nitro)was introduced into 1,8-naphthalimide that was synergistically combined with the diacyl group on 1,8-naphthalimide makes the electron of naphthalimide chromophore deficiency seriously,thereby could be react with anion by electrostatic interaction for sensing anion.In this paper,a simple 3-nitro-1,8-naphthalimide derivative was used as a fluorescent probe 3,and a novel method for the detection of cyanogen ions was developed.Through the experiments of UV-vis titration,fluorescence emission titration and 1H-NMR titration,the results show that the probe 3 has high sensitivity,specificity and excellent selectivity to cyanide ions,and can realize colorimetric and fluorescence detection of cyanide ions.This work confirmed and developed for the first time a novel sensing strategy based on cyanide-induced nucleophilic aromatic substitution of hydrogen with denitrative and cyanylation-hydroxylation mechanisms for the detection of cyanide ions.Further,a series of novel aromatic naphthalimide etherified derivatives 4a-4g were prepared with simple and efficient in one pot by aromatic nucleophilic substitution of 3-nitro-1,8-naphthalimide with alkyl alcohols and aromatic alcohols.Compared with the previous synthesis of aromatic ether derivatives,this method has the advantages of mild reaction conditions,high synthesis yield,ligand-free and no need alkali,and metal catalysis,etc.In this work,a novel method for the preparation of naphthalimide aryl ether derivatives was developed for the first time.