Design and Synthesis of Perfluoroalkyl Decorated BODIPY Dye for Random Laser Action in a Microfluidic Device

New and highly emissive 2,6-diacetynyl and 2,6-bis-(phenylacetynyl) functionalized pentamethyldifluoroboron-dipyrromethane (BODIPY) derivatives, (FBDP1-2) with perfluorinated pendants groups at the boron center have been synthesized successfully by the combination of two strategies, extending the π-conjugation and functionalization at the boron centre. The newly synthesized dyes have been characterized unambiguously by various analytical tools such as multinuclear NMR, MALDI-TOF, including single crystal XRD analysis. The dyes (FBDP1-2) exhibit excellent photophysical properties in the yellow to the red spectral region (λabs = 530 nm, 555 nm and λem = 555 nm, 596 nm respectively) with relatively good Stokes shift (849 cm-1 and 1240 cm-1), high quantum efficiency (φF=0.72 and 0.61) and excellent brightness (2.95 × 104 and 2.38× 104 M-1cm-1). Most importantly, under transverse pumping condition at 532 nm, the dyes show efficient and stable laser action, having a good tunable range (20 nm and 13 nm) with maximum lasing efficiency of 45% and 38% for FBDP1 and FBDP2 respectively. Moreover, random lasing behavior of FBDP1 has been investigated in dye-circulated polydimethylsiloxane (PDMS) based disordered microfluidic device. The appearance of randomly positioned sharp spikes with a full width at half maxima (FWHM) of less than 0.3 nm around 555 nm indicates the random laser (RL) emission. The relationship between input pump energy and output random lasing intensity has also been demonstrated, with the random lasing threshold of 0.5 mJ.