Synthesis, Thin Film Preparation And Sensing Application Of Novel Perylene Imide Derivatives

Organic amines are generally toxic and irritating and are a common class of contaminants that are widely found in the atmosphere and water.Excessive organic amines in the environment may threaten human health.Many aromatic amines are considered to be potential carcinogens.For example,aniline and o-toluidine can be absorbed into the body through breathing or through the skin,causing a series of related diseases.At the same time,they can also be used as markers for lung cancer;phenylenediamine gases such as o-phenylenediamine,m-phenylenediamine have mutagenicity and teratogenic effects;p-phenylenediamine can cause allergic reactions,such as acute inflammation or dermatitis.Therefore,it is of great significance for the rapid,accurate and sensitive detection of organic amines,especially aromatic amines,in the air.To date,different methods have been developed to detect organic amines,including photometry,chromatography,and electrochemical methods.However,these methods are often demanding to test conditions,expensive instruments,and difficult to implement online monitoring and wide application.Among the many detection methods,fluorescent sensors have attracted much attention due to their high sensitivity,good selectivity,low cost,rich output signals,and many detectable objects.As an n-type organic semiconductor,perylene bisimide(PBI)has been widely used in laser dyes,organic optoelectronic devices,sensor materials,etc.due to its high fluorescence quantum yield,photothermal stability,and excellent optoelectronic properties.However,the application of PBI derivatives is limited due to their poor solubility,high hydrophobicity and easy formation of H aggregates.To cope with these problems,PBIs are generally functionalized by introducing bulky substituents at the imide or the core positions to impede co-facial π-π interactions,which represents a convenient strategy to control solubility and decrease aggregation between PBI units.Previous studies have shown that PBI-based fluorescent sensors have shown broad application prospects.In recent years,the introduction of supramolecular functions and the construction of supramolecular functional materials of PBI have further expanded its application in the field of optical sensing.Based on the above discussions and research progress in our laboratory,two kinds of fluorescent films with PBI derivatives as the sensing units were designed and prepared.Their photophysical behavior and sensing performance were systematically studied.Specifically,this thesis mainly includes the following three parts:In the first chapter,the molecular design and detection mechanism of fluorescent sensors,liquid phase sensors,thin film sensors and fluorescence sensor arrays are introduced.Then the state of the art of fluorescent sensors especially PBI-based fluorescent sensors are summarized,which are described in two aspects:liquid phase sensing and gaseous phase sensing.The field of liquid phase sensing mainly involves the detection of analytes such as metal ions,anions,and biological macromolecules.The field of gaseous phase sensing is described around the detection of volatile toxic and harmful gases.In the second chapter,we describe a new type of fluorescent sensing film based on a copolymer that use a PBI as amine-sensitive unit and introduce an optically inert monomer 2-hydroxyethyl methacrylate to impede H-type aggregation of the PBI units.Meanwhile,the presence of numerous hydrophilic OH groups will assist the adsorption and enrichment of amines on the film surface based on the H-bonding interactions.Owing to the photoinduced electron transfer process between PBI moieties and the aromatic amines,the prepared film shows extremely high sensitivity,high selectivity,and full reversibility to aromatic amines,especially aniline vapor.We also acquired reproducible quantitative data using a home-made sensing platform to simulate real applications.The kinetic information of the physical adsorption and recovery processes help to differentiate aromatic amines from aliphatic analogs.The sensing film is expected to find potential application in the diagnosis of diseases such as lung cancer.In the third chapter,an amphiphilic perylene bisimide derivative was designed and synthesized by using a PBI as sensitive unit and introducing a melamine substituent at the imide position to provide multiple hydrogen bonds.Based on the Langmuir-Blodgett(LB)technology,the amphiphilic molecules are self-assembled at the molecular level at the gas/water interface,thus obtaining a uniform film with highly ordered molecular arrangement.Preliminary tests show that the film can distinguish between three important isomers of o-phenylenediamine,m-phenylenediamine and p-phenylenediamine,and the systemic sensing performance test and its mechanism study are still in progress.In addition,a co-assembled LB film based on the multiple hydrogen bonding between melamine and barbituric acid is also being prepared to further optimize the aggregation structure and sensing behavior of the film.