Synthesis And Optical Properties Of New Perylene Diimides

Perylene diimide(PDI) derivatives have been more widely applied as functional materials, such as organic photovoltaic devices, organic electronic devices, organic light-emitting diodes(OLEDs), fluorescence and near infrared dye, as a result of their excellent thermal, photochemical stability and a high fluorescence quantum yield, and its has a strong absorption from visible to infrared region. Therefore, Luminescent properties and other physical properties of PDI derivatives has been hot pot for researchers. Driven by the demands of diverse application, it’s very important method to obtain the PDI material with novel photophysical properties by the modification on molecular structure of PDI. In this paper, a series of new type PDI derivatives were designed and synthesized, and their properties were investigated.1、Three new pyrenyl perylene bisimide compounds were synthesized by the substitution reaction of intermediate 2Br-PDI(b) and pyrene derivatives. The spectral results of these compounds showed that their spectral characteristics were affected by changed the substituent on the bay- of perylene bisimide. Their obsorption spectrum became very intense and absorption peaks generated bathochromic shift due to electronic donors of pyrenyl. In addition, spectra of three molecules in different solvents indicated that there existed molecular aggregation and their peaks were broadened in the polar solvent.2 、 Eight perylene compounds were synthesized based on phenylboronic acid,1-pyrenylboric acid, 4-pyrenylboric acid ester, 4-hexahydropyrenylboric acid ester compounds by C-C Suzuki coupling reaction. Besides, C4 and D4 molecules were obtained by closed ring reaction of the C3 and D3 compounds under the light conditions. Due to the difference of conjugation and inductive effect, they have different luminescent properties. In dilute solution, there were three peaks in the absorption spectra of B3, C3 and D3. It implied that they were material with low bond gap which can be applied in organic photovoltaic device. In film, there existed aggregation between molecules for the C3 and D3. Compared with perylene bisimides,compounds C4 and D4 showed broader absorption extended to 650 nm. Spectral and electrochemical measurement of compound C4 and D4 with enlarged p-conjugated system showed decrease of energy gap, which indicated effective conjugation of perylene bisimide moiety and pyrene(6-hexahydropyrenyl) moiety.3 、 Two new perylene compounds were obtained based on the 1,6,7,12-terta(4-tert-butyl phenoxy)-3,4,9,10-)tetracarboxylic dianhydride by modification on imide N atoms of PDI. Spectral test of compound Y1 and Y2 showed that there existed aggregation between molecules for the Y1 and Y2, and further confirmed that the imide substituent on N atom is not too much influence on its absorption spectra.The above results indicate that photoelectric chemical properties can be efficiently improved and controlled by the reasonable modification on active site of PDI.