Synthesis And Photoelectric Properties Of Pyridinium And Esters Derivatives Based On Naphthalene And Pyrene

Electrochromic materials are environmentally friendly,economical and practical,and have attracted the attention of many researchers.Among the electrochromic materials that have been reported,pyridinium and ester derivatives have excellent electrochromic properties,which have become a research focus in recent years.The thesis mainly investigated the synthesis of pyridine salts and esters derivatives with naphthalene and pyrene as the parent,and explored the electrochemical properties and electrochromic properties of the compounds.The specific research contents were as follows:The first chapter described the development history of electrochromism,classification of electrochromic materials,the structure of electrochromic devices,performance parameters of electrochromic devices and the application of electrochromic devices.Finally,the purpose and significance of the selected topic of this article were put forward by expounding the research progress of materials related to this paper.In chapter 2,by using 1,4,5,8-naphthalenetetracarboxylic dianhydride as the raw material,and six kinds of 1,4,5,8-naphthalene diimide derivatives(NDIs)with different R substituents were synthesized by acylation reaction.Using proton nuclear magnetic resonance spectroscopy,carbon nuclear magnetic resonance spectroscopy,high-resolution mass spectrometry and other means to confirm the molecular structure of compounds.The electrochemical performance of these compounds was tested by cyclic voltammetry,and the experimental results show that these compounds have good electrochemical stability.The photoelectric properties of the electrochromic devices based on NDIs have been tested by UV-Vis absorption spectroscopy,spectral dynamics and chronoamperometry.The influence of different R groups on electrochromic performance was investigated.The results showed that when a certain voltage was applied,the NDIs compounds change from a colorless bleached state to a yellow colored state,and have the advantages of low driving voltage,fast response time and high coloration efficiency.In chapter 3,using 1,4,5,8-naphthalenetetracarboxylic dianhydride as the raw material,seven kinds of N,N'-di(4-pyridyl)-1,4,5,8-naphthalene diimide salt derivatives(DPNDIs)were synthesized by acylation reaction and N-alkylation reaction.The structure of compounds has been confirmed by ¹H NMR,¹³C NMR,HRMS and other methods.Cyclic voltammetry was used to test the electrochemical performance of these compounds,and the results show that the compounds have good electrochemical stability and electrochemical activity.The photoelectric properties of the devices based on these compounds were tested by UV-Vis absorption spectroscopy,spectral dynamics,and chronoamperometry.The effect of different R substituents on the electrochromic properties was explored.The performance of DPNDIs was compared with that of NDIs described in chapter 2.When a certain voltage is applied to the electrochromic devices,both and NDIs exhibited similar the colored state.It's interesting that DPNDIs have a lower driving voltage,a higher optical contrast and a good cycle stability.This is attributed to the introduce of pyridine salt into the chemical structure.In chapter 4,eight mono-,di-,tri-,and tetra-ester-substituted pyrene derivatives were synthesized,and their electrochemical and photoelectric properties were characterized.By using pyrene as the raw material,three kinds of mono-ester-substituted pyrene derivatives were synthesized by Friedel-Crafts acylation reaction,oxidation reaction and esterification reaction.By using 1,6-dibromopyrene as raw material,one di-ester-substituted pyrene was synthesized via cyano substitution reaction,hydrolysis reaction and esterification reaction.Three tri-ester-substituted pyrene derivatives were synthesized by bromination reaction,cyano substitution reaction,hydrolysis reaction and esterification reaction.By using 1,3,6,8-tetrabromopyrene as raw material,one tetra-ester-substituted pyrene was synthesized by cyano substitution,hydrolysis and esterification.The structure of these compounds was confirmed by ¹H NMR,¹³C NMR,HRMS and other methods.The electrochemical and electrochromic performance of the prepared electrochromic devices was tested by cyclic voltammetry,UV-Vis absorption spectroscopy,spectral kinetics,and chronoamperometry.Experimental results show that the substitution of different R substituents and different chemical sites have an impact on the electrochromic properties.Compared with the electrochromic properties of DPNDIs,experiments show ester-substituted pyrene derivatives perform better in response time,optical contrast,cycle stability,and coloration efficiency.This was ascribed to the increase in the degree of conjugation of the parent molecule and the introduction of ester groups.In chapter 5,the main research results of this thesis were summarized,and the future development direction of this research field was prospected.