Synthesis, Characterization and Optical Properties of a Bay- Functionalized Perylene Dye:N, N′-Didodecyl-1,7-di(3-methylphenoxy)- perylene-3,4:9,10-tetracarboxylic Acid Bisimide

Perylene chromophore has an excellent aromatic conjugation and offers numerous advantages in many fields of application. One of their greatest advantages is the capability to functionalize the chromophore at its core/bay and imide positions with various substituents according to the desired application. In the present research on perylene dyes, we have synthesized a new core substituted perylene diimide in three consecutive steps focusing the application toward solar cells. Firstly, the starting raw material perylene dianhydride was brominated at 1,7- positions of the perylene chromophore to yield brominated dianhydride (Br–PDA). The product was imidized in the second step with a long dodecyl alkyl chain to yield brominated perylene diimide (Br-PDI). Finally, the targeted core substituted perylene diimide (PDI-m-Cresol) was synthesized upon bay substitution of perylene chromophore with m-cresol. The final compound is highly pure and characterized by FTIR, UV-vis and Emission measurements. For comparison, photophysics of the intermediate products were carried out in parallel. The absorption spectra of three perylene derivatives in nonpolar aprotic solvents and polar protic solvents show characteristic aromatic π–π* transition absorption peaks. In contrary, absorption in dipolar aprotic solvents shows irregular additional absorption bands (Br-PDA in NMP; Br-PDI in DMF; and PDI-m-Cresol in DMF and NMP) at higher wavelengths which were remained after microfiltering the solution. Interestingly, the emission spectra of the three perylene derivatives have shown traditional three characteristic emission peaks and were not influenced by additional weak absorption bands. Keywords: Perylene dyes, perylene derivatives, Bay-substitution, characterization of perylene derivatives.