Double 3-Ethyl-2,4-dimethylpyrrole Configured Fluorescent Dye with Fluorine-Boron as the Bridge

Dipyrrolydiketones BF2 complex was synthesized and characterized by NMR, HRMS, and single crystal diffraction. In non-polar environment, this BF2 containing dye emitted bright blue-green fluorescence. No significant spectra shift was observed both in absorption and emission spectra, which indicates the insensitivity of absorption/emission toward environment. The alkyl substituted pyrrole rings lead to its highly emission character in solid state by enhancing the distance between dye molecules. Absolute quantum yields were determined to be 0.51-0.78/0.36 in selected organic medium and solid state, respectively. The emission dynamics was investigated by fluorescence lifetime and both monoexponential and bi-exponential decay was observed.