Basic structural modifications for improving the practical properties of BODIPY

The review considers the results of research by scientists from different countries in the field of synthesis and photophysical property study of known BODIPY. We focus on describing the main ways the BODIPY structure modifying by substituting the pyrrole rings, the meso-spacer, and the boron atom of the indacene core with different nature substituents and changing the spectral and other practically significant BODIPY properties associated with a particular type of their modification. In addition, we have considered the effects of alkylation, halogenation, nitration, amination, and arylation at the meso-spacer and/or pyrrole rings, boron atom; pyrrole rings annulation; meso-aza-substitution, covalent oligomerization through direct σ-bonds or spacers. Most of these approaches have a very significant and individual effect on the photophysical properties, hydrophobicity or hydrophilicity of dyes and consequently, on their practical application possibility. In the general case, BODIPY modification approaches considered above make it possible to vary the absorption and fluorescence bands position of BODIPY in the range from UV to NIR spectral regions (from 400 to 1000 nm). Depending on the features of BODIPY functionalization, as well as on the properties of the medium, the quantum yields of fluorescence, phosphorescence, and singlet oxygen generation of BODIPYs can be changed from 0 to 100%.