Construction Of Naphthalimide-based Self-assembly Systems And Its Detection Performance Of Acyl Chlorides

Supramolecular self-assembly system is a kind of soft material formed by non-covalent bond,which has been preferred by scientists due to its wide application in many fieds.Acyl chlorides such as phosgene and oxaloyl chloride are widely used in medicine,pesticide and intermediates of organic synthesis.However,acyl chlorides are generally highly toxic.It has been revealed that exposure to 20 ppm of phosgene in humans can cause severe lung and respiratory damage within 20 minutes,while exposure to high concentrations of phosgene is lethal.Therefore,the real-time and sensitive detection of acyl chlorides becomes an urgent problem to be solved.In this paper,several supramolecular self-assembly systems were designed and synthesized,which can be used for the rapid and visual detection of acyl chlorides.The main research contents are as follows:（1）Two naphthalimide derivative chemical sensors（1 and 2）with ethylenediamine and 1,3-diaminopropane terminal groups were designed and synthesized to sensitively detect different acyl chlorides by reacting with ethylenediamine and propylene diamine groups at 4-position of naphthalimide.The results showed that compound 1 could detect sulfoxide chloride and oxaloyl chloride sensitively in solution and film,and the solution color changed obviously and fluorescence quenching was performed.Compound 2 could only selectively respond to oxaloyl chloride in solution and film state.The results show that the function of the sensor is obviously changed by the structure of the end group,which provides theoretical guidance for the design of the self-assembly sensor of the naphthalimide derivative group.（2）A new 4-amino naphthalimide derivative,NIA-4,was designed and synthesized,which could form stable organic fluorescence gel in six solvents.Compound NIA-4showed sensitive response to highly active acyl chlorides due to its weak nucleophilicity of the 4-amino group in naphthalimide.Compound NIA-4 can detect SOCl₂,phosgene and（COCl）₂ in solution,gel and film states,exhibiting changes in color,fluorescence and gel state,enabling rapid and visual detection of acyl chlorides.This study will provide a new way to construct a multifunctional self-assembly system for acyl chlorides detection.（3）A noval 3,4-diamino-1,8-naphthalimide gelator DIAN was designed and synthesized,which can form stable gel in single or mixed solvents.Many sensors cannot distinguish phosgene from oxaloyl chloride because of their similar structures.Compound DIAN could detect phosgene in toluene solution in ratio mode,and the fluorescence of the solution changed from orange to light green and the color of the solution also changed.After oxaloyl chloride and sulfoxide chloride were added,the fluorescence quenching behavior occurred along with the color change.The film DIAN also underwent ratio change when exposed to phosgene gas,while the fluorescence quenching behavior occurred when exposed to sulphoxide chloride and oxaloyl chloride.This provides a new way to selectively distinguish phosgene from oxaloyl chloride and sulfoxide chloride.