Synthesis, Assembly And Sensing Applications Of Novel Naphthalene Diimide Derivatives

Among the gaseous pollutants,organic amines are byproducts of cell growth and decomposition products generated by biological corruption.Meanwhile,as a kind of important chemical raw material,organic amines have also been widely used in various areas such as the chemical industry,cosmetic products,food additives,etc.It means that organic amines could diffuse into air from garbage incineration,wastewater,construction materials,automobile exhaust,factory emissions,etc.The excess of organic amines in air would seriously damage the ecological environment and cause severe threats to human health.For example,the content of aniline/o-toluidine in the air over that the human body can withstand,could give rise to Methemoglobinemia.In fact,some of the organic amines are usually considered as air quality indicators and also used as biomarkers for certain types of the diseasessuch as uremia,hepatopathy,and lung cancer.Therefore,developing effective methods for the detection of organic amines is of great importance.Nowadays,developing a fast,accurate and sensitive method for detecting aniline has been a major research topic for research workers.At present,the methods of aniline monitoring mainly include spectrophotometry and chromatography.However,required conditions of the two methods are very harsh and the equipments are quite expensive which make them hard to be put into practice.Hence,researchers have developed new fluorometry,flow injection spectrophotometry,kinetic spectrophotometry and other methods to detect aniline.In fluorescence method,the fluorescence sensing film obtained by fixing the fluorescent reporter group onto the surface of the solid substrate shows the advantages of being reusable,easy to be deviceed and rare pollution to the testing system.In addition,the fluorescence method has high sensitivity,good selectivity,rich output signals(spectral shape,fluorescence intensity,intensity ratio,fluorescence lifetime,fluorescence anisotropy,etc.),which endows the fluorescent film great potential for sensing applications.Therefore,for the organic amine gas phase detection,the development of high-performance fluorescent film sensor has a special significance.It is found that the factors determining the sensing properties of the fluorescent film are the choice of fluorescent species,the thickness and the microstructure of films and the matrix effect.In the fluorescent species,aromatic diimides with modifiable structure and excellent optical properties are always being used as the reporting group of fluorescent sensor.Compared to pyromellitic acid diimide,perylenediimide and naphthalimide materials have high fluorescence quantum yield,photothermal stability and redox properties,which make them widely used in photoelectric materials,information display and storage,biological recognition and sensing.In this paper,the naphthalimide was selected as a fluorescent core unit due to its modificable molecular structure and good solubility.Specifically,the thesis includes three parts as follows:The first chapter summarizes the structural characteristics,modification methods and application fields of three different aromatic diimides.Their applications were briefly introduced in the fields of organic optoelectronic semiconductor materials,catalysis,ion detection and gas identification.Naphthalimide derivatives could form various morphology by gelling,D-A,ion coordination and other interactions.It not only enhances researchers' understanding of naphthalene,but also expands the application of naphthalimide prospects.In the second chapter,the naphthalimide derivatives TDBNDI with long alkyl chain were designed and synthesized using molecular gelation assembly strategy.Modification of naphthalene diimide(NDI)with long alkyl chains resulted in a photochemically stable,fluorescent 3,4,5-tris-(dodecyloxy)benzamide derivative of NDI(TDBNDI)with good common organic solvents.Further studies revealed that TDBNDI could form gels in 9 of the 18 solvents at a concentration of 2.0%(w/v),and the critical gelation concentrations of five gels were lower than 1.0%(w/v),indicating the high efficiency of the compound as a low-molecular mass gelator(LMMG).Transmission electron microscopy,scanning electron microscopy,and confocal laser scanning microscopy studies revealed the networked fibrillar structure of the TDBNDI/methylcyclohexane(MCH)gel.On the basis of these findings,a fluorescent film was developed via simple spin-coating of the TDBNDI/MCH gel onto a glass substrate.Fluorescence behavior and sensing performance studies demonstrated that this film is photochemically stable,and sensitive and selective to aniline vapor.Notably,the response is instantaneous,and the sensing process is fully and quickly reversible.The superior performances laid a solid foundation for sensing device.In the third chapter,the peritectictetracarboxylic acid is combined with naphthalene diimide by electrostatic action to construct the sensing element and it is expected to be able to obtain a fluorescent sensing film with excellent assembly morphology and predominant sensing performance.It was found that the PTCA/s-TDBNDI complex cannot be directly obtained by mixing the perylenetetracarboxylic acid in water with the TDBNDI in organic solvent.Instead,the perylenetetracarboxylic acid was modified into perylenetetracarboxylic acid,and the single-terminal primary amine s-TDBNDI compound was modified into iodinated s-TDBNDI-I compounds,and then,the two-phase reaction was carried out to produce AgI.Therefore,the free cationic and cationic were forced to bind to obtain the target compound.And in the interest of time,the film-forming method and the sensing performance and other related work is ongoing.