Design, Synthesis And Aggregation Study Of Perylene Diimide Derivatives Containing Electron-donating And Electron-withdrawing Groups

Perylene diimide derivatives are materials with excellent thermal stability and uniqueoptical physical activity and photochemical properties, so they have wide range potentialapplications in organic solar cells, organic electroluminescent devices, organic field-effecttransistors and liquid crystal field. Therefore, designing and synthesising of a new-styleperylene diimide derivative molecule with high solubility, and investigating into itsstructure-activity relationship with its self-assembly properties have already become a hottopic in the field of scientific community.In this study, two perylene diimide derivatives containing electron-donating andelecton-withdrawing groups : N, N’- 4-methoxybenzeneamine -3, 4, 9, 10-perylene fourcar boxy diimide (DOMPP) and N, N’- 4-(Trifluoromethoxy)aniline -3, 4, 9, 10-perylenefour car boxy diimide (DFOMPP) were synthesized and characterized by FT-IR,1H NMR.The thermal stability was tested by DSC; besides, their photophysical properties andaggregation structures were studied and compared by different testing methods includingUV-vis absorption spectroscopy, Fluorescence emission spectroscopy, Polarizingmicroscope and Field emission scanning electron microscope (SEM).The results showed that DOMPP and DFOMPP had good thermal stability, themelting point was 367℃and 368℃, respectively. Moreover, the thermal stability ofDFOMPP was obviously improved.The accumulation capacities of DOMPP and DFOMPP were enhanced with increasedsolubility in solution. Moreover, compared with DOMPP, DFOMPP was easier to getlarger number and more neat crystals. In addition, DOMPP and DFOMPP had the similarsheet liquid crystal phase texture.The photophysical properties and aggregation structures of DOMPP and DFOMPP indifferent solutions, different concentrations and different ratios of CH2Cl2-Acetonesolution were investigated by UV-visible absorption spectra and Fluorescence emissionspectra. The results showed that the intensities of light absorption and light emissionmarkedly declined with their decreased solubility in solution. Moreover, in different ratiosof CH2Cl2-Acetone solution, with the acetone content increasing, the absorption peaks of DFOMPP appeared obvious blue shift and red shift, therefore, it showed that its molecularaggregation changed with the increase of the poor solvent.DOMPP and DFOMPP were self-assembled into nanoparticle aggregates. With thedifferent solubility in solution, DOMPP showed morphologies such as strip, verticallyaligned strip, While DFOMPP showed different morphologies such as rod, triangle,polygon, sphere.