A blue light emitting perylene derivative with improved solubility and aggregation control: Synthesis, characterisation and optical limiting properties

We report the synthesis and characterisation of 3,4,9,10-tetra-(12-alkoxycarbonyl)-perylene, a blue emitting organic material with controlled aggregation and improved solubility. The dye has a UV–Vis maximum absorption peak at 472 nm. Room temperature photoluminescence reveal a blue emission peak at 489 nm. Thermo gravimetric analysis (TGA) performed in air show the product to be thermally stable up to 300 °C. Dynamic scanning calorimetry (DSC) did not show a liquid crystalline phase normally present in 3,4,9,10-tetra-(n-alkoxycarbonyl)-perylenes for 2 ⩽ n ⩽ 9 where n is the number of carbon atoms in the alkyl chain. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were employed for aggregation studies of the dye showing that molecular stacking is not favoured. The Tauc relation applied to the UV–Vis absorbance cut-off wavelength at 500 nm was used to evaluate the optical band gap of the material as 3.81 eV and an exciton binding energy of 1.2 eV. Open-aperture Z-scan proved the molecule to be nonlinear optically active with an optical limiting extinction coefficient of 3.0 × 10−10 cm W−1. Experimental evidence shows that the optical limiting ability is attributed to nonlinear scattering.