Fabrication Of Low-dimensional Perylene Imide Derivatives-based Functional Materials By Phase Transfer

Low dimensional material is the foundation of materials in the information age,and the low-dimensional nano functional materials (nanoline, nanostick, nanobelts,etc)have become the hot spots in the field of nano science and nanotechnology. Mostof the one dimensional nanostructures mainly focuses on the inorganic materialsystems, but for organic materials only a few related news have been reported. Organicpolymers with conjugated structure have been widely used in the light emitting diodes,field effect transistors solar cells and other functional devices for their outstandingphotoelectric properties. Then it’s very significant to know how to make organicπconjugate with special accμmulation way(nanometer scale pipe, line, sitck and layer)through a more simple convenient technique,which also have vast potential for futuredevelopment. Based on the literature review, two kinds of perylene diimide derivativesN-PBI and PBI were synthesized then through phase transfer and solutionself-assembly methods, the perylene imide functional small molecules were formedinto the orderly low-dimensional functional supramolecular material, meanwhile theaffregate structure and properties were preliminary characterized.When studied the aggregate structure of N-PBI through solution self-assemblyway, it was found that in dichloromethane, chloroform and dioxane solvents N-PBI didnot formed low-dimensional aggregates, whereas in the acetone solvent, it formed alamellar structure; in methyl cyclohexane solvent, N-PBI formed rod and the lamellarstructure with smooth surface. By further study as UV-Vis absorption spectra andfluorescence spectra, it was found that, the solution self-assembly of N-PBI formedthe H-type aggregate structure. The results of N-PBI aggregate structure using phasetransfer method as following:when the methanol/chloroform volμme ratio was largerthan2:1, the N-PBI aggregates formed the large size dimensional rod-like aggregatestructure, UV-vis spectroscopy indicated that it was a typical face-to-face stacking H-type aggregates.however, when the methanol/chloroform volμme ratio was less than1:1, N-PBI aggregates owned a short rod-like structure, its UV absorptioncharacteristics had a greatly red-shifted, showing the typical J-type aggregates.When studied the morphology and structure of PBI by the solvebt self-assemblymean, it was found that solvents had large influence on the morphology ande structure.the PBI in dichloromethane and toluene solvent could form a ordered, smooth surfacelow dimensional rod-like aggregates whose diameter was about0.1-0.5μm, as for the solvent of acetone, it was formed to a long cylindrical aggregates, witha diameter ofabout0.8μm; in addition, in the dioxane and the chloroform solvents, PBI werenotformed low dimension aggregates. Furthermore, UV-Vis absorption spectrμm ofPBI aggregatesindicated that in dichloromethane and toluene solvents, PBI formedJ-type aggregates, which was completely different from the molecular packing modelof the N-PBI aggregates. For the angular, length of a colμmn structure of PBIaggregates prepared by methanol and chloroform two-phase solvent phase transfer, andfor homogeneous structure, smooth surface of lamellar aggregates formed from hexaneand chloroform two-phase solvent, it was found that two kinds of aggregation structurewere typical J-type aggregates by futher investigation.Finally the morphology and structure of the solvent self-assembley of PBI and BD(4,4-bipyridyl) in different solvents were investigated. The study founded that, thePBI/BD in dioxane, chloroform, dichloromethane did not formed a ordered aggregatestructure; while in toluene and acetone solvent, a ordered J-aggregate structure wasformed. Based on the PBI in different solvents, the study of molecules packingaggregates with different ratio of PBI/BD in toluene solvent was found that the π-πstacking direction of PBI aggregates in dichloromethane, toluene solvent was inaccordance with the he direction of the long axis, while the π-π stacking direction ofPBI/BD (1:4) and PBI/BD (1:0.5) aggregates is perpendicular to the direction of thelong axis.The results above showed that, the molecular structure, solvents and theself-assembly methods all had an important impact on the aggregate structure, whichprovided new means for preparing the large scale low dimensional materials withperylene imide to as the building blocks,and it also laid theoretical foundation fordeeply research on the supramolecular assembly process and the mechanism of theaggregates structure.