Synthesis And Controlled Self-Assebly Behavior Of Perylene Diimdes Containing Donnor Groups

Perylenetetracarboxylic diimide derivatives (PDIs) exhibit excellent light and thermal stability, chemical inertness, high fluorescence quantum yield, high charge mobility, as well as good electron accepting ability, which make perylene diimides the most promising for application in many fields, such as solar cells, organic field effect transistors, biological fluorescence probes, electroluminescence and self-assembly. Recently, many perylene diimide derivatives with specific functions have been synthesized by means of modification at bay position or/and imide nitrogen of pristine perylene diimide. For example, introducting the electron donor units into the perylene diimide which is used as electron acceptor improves the solubility of perylene diimide, which is necessary for self-assembly in solution, meanwhile, the donor-acceptor-donor systems promise facilitated charge transfers from donor to acceptor, and promote the subsequent charge sergregation and formation of charge-transfer complexes, which makes it good candidate for organic storage materials. Compared with traditional organic storage materials based on polymer, make the memory devices by self-assembled layers exhibiting lower threshold voltage and rapider response speed, which have potentially broad application in the field of organic storage materials.In this paper,6-carbazol-9-ylhexylamine and 2-carbazol-9-ylhexylamine have been designed and synthesized.6-carbazol-9-ylhexylamine, 2-carbazol-9-ylhexylamine and 2-thiopheneethylamine were chosen as electron donor groups and then introduced into the imide nitrogen of perylene diimide, respectively. The differences of photophysical properties and molecular configurations among these perylene diimides have been studied. The results demonstrated that the introduction of donor units into perylene diimide can broaden the photo-absorption region, and at the same time result in fluorescence quenching due to intramolecular electron and energy transfer process. Also, with shortening the spacer between donor and acceptor, the electron delocalization becomes higher, which leads bathochromic-shift. In addition, spatial structure of PDIs is significant influenced by the modification at bay position, the dihedral angle between two naphthalene is 15.61°, which is caused by the introduction of 4-tert-butylphenoxy to bay position. The spatial structure is almost irrelevant to the substituents in imide nitrogen.By means of the rapid dispersion method, the self-assembly behavior of PDI-2Cz was studied and the packing model of self-assembly was discussed. PDI-2Cz self-organized into regular nanorods. These nanorods have proven to be hexagonal with single crystal nature. All the configurations of molecular are inclined to be stair-step shape. The supramolecular aggregation is formed by intermolecular π-π stacking.The PDI-6Cz self-assembled films which used as active layer of sandwich device was obtained by surface-supported solvent vapor annealing. The memory behaviors of the Au|PDI-6Cz layer|ITO sandwich device were investigated by semiconductor method. The PDI-6Cz self-assembled films possess good electrical bistabilities, the threshold voltage is 0.8 V, the on/off switching ratio is above 104, the equilibrium time is 30 ns. Compared with traditional storage materials based on polymer, perylene diimide self-assembled layers exhibit lower threshold voltage, higher on/off ratio and rapider response.