A new 3-substituted BODIPY dye: Synthesis, crystal structure, photophysical, non-linear optic and OLED properties

Abstract

A BODIPY derivative (compound 2), substituted with 4-nitrophenyl at the meso position and its 3-pyrrole substituted derivative (compound 3) were synthesized and characterized. The structure of compound 3 was elucidated by single crystal X-ray diffraction study. The Photophysical properties of compounds 2 and 3 were studied in various solvents with different polarities. The expansion of the π-conjugation by introduction of the pyrrole ring to 3-position of the BODIPY core results in a considerable red shift in the absorption and emission bands. Also, photophysical properties of compounds 2 and 3 was affected by the solvent polarity. Compound 3 showed stronger fluorescence in non-polar solvents (ΦF = 0.049 in Hexane). In order to establish the effect of the pyrrole attachment, the synthesized compounds 2 and 3 were optimized at the level of computational chemistry, DFT/B3LYP/6–31+G(d,p). The highest occupied molecular orbital energy (EHOMO), the lowest unoccupied molecular orbital (ELUMO), the energy gap (ΔE) parameters and contour diagrams obtained from the optimized structures were investigated. The nonlinear optical (NLO) and light emission (OLED) properties of the compounds were investigated computationally on the basis of polarizability parameters and Marcus theory, respectively.