Synthesis and spectral properties of symmetrically arylated BODIPY dyes: Experimental and computational approach

In this study, a series of symmetrically arylated BODIPY dyes were synthesized using a pre-functionalization method, and their structures were characterized by several spectroscopic methods. The relationship between the aryl substitution pattern and the photophysical and electrochemical properties of the dyes was investigated using experimental and computational methods. It was found that electron-donating π-conjugated groups at the meso position and electron-accepting π-conjugated groups at the C3/C5 position led to blue-shifted spectra, while the opposite substitution pattern resulted in red-shifted spectra. Additionally, inductive electron-donating alkyl groups at the meso position produced a blue spectral shift and an alkyl group at the meso position significantly increased the fluorescence quantum yield compared to the arylated counterparts. Computational investigations revealed that a thioanisyl group at the C3/C5 position resulted in a significantly narrow band gap. These results provide valuable insights into the design and development of new BODIPY dyes with tailored properties for various applications.