Symmetrical and unsymmetrical perylene diimide dyes for photovoltaic applications: Chiral, amphiphilic and electrochemical properties

ABSTRACT: In this research, four novel perylene derivatives (BPDI, LPMI, LPDI and LPPDI) have been successfully synthesized. The synthesized compounds have been characterized and investigated in detail by NMR, IR, UV-vis, emission, DSC, TGA, elemental analysis, CV, SWV and CD. The specific optical rotation values of LPMI, LPDI and LPPDI were measured as +1191.5, +201.7 and -1647.5, respectively at 20 oC. The compounds showed high thermal stabilities. The initial decomposition temperatures were calculated as 361 oC for BPDI, 387 oC for LPMI, 356 oC LPDI and 415 oC, for LPPDI. For LPPDI in NMP, two isosbestic points were observed at 533 and 611 nm which confirmed the presence of overlapped monomer and excimer emissions in the temperature range 10 oC to 80 oC. Fluorescence quenching of chiral dyes; LPMI, LPDI and LPPDI in m-cresol have been attributed to a charge transfer interaction. Moreover, the excited state of the four dyes can decay only by fluorescence in solid state mainly due to O-H...N hydrogen bonds. The novel photonic perylene dyes have a great potential in various fields such as solid state lightning technology, dye-sensitized solar cells and photomedicine. Keywords: Amphiphilic, chiral, hydrogen-bonding, controlled self-assembly, perylene, DSSC. …………………………………………………………………………………………………………………………