From blue to red. Reaching the full visible spectrum with a single fluorophore: BODIPY

BODIPYs (Boron-dipyrromethenes) are a class of fluorophores widely used in a plethora of scientific applications in material science and biomedicine due to their exceptional optical properties. The modulation of the absorption and emission wavelengths of BODIPYs is an area with significant growth opportunities, allowing these compounds to be tailored for specific applications. This review addresses different synthetic strategies that could modify their electronic and optical properties of the BODIPY core, mainly the absorption and emission wavelengths (λ_abs = 422 nm - λ_emis = 753 nm and quantum yields up to Φ_c-hex = 100 %). These methodologies include reactions like nucleophilic substitutions with (chiral/achiral) primary and secondary amines, alkyl/aryl alcohols, active methylenes, as well as Liebeskind-Srogl, Sonogashira, Heck, and Suzuki cross-coupling reactions at the meso and peripheral positions of the BODIPY core. These synthetic strategies incorporate specific functional groups that influence the π-system conjugation, generation of AIEgens, and Donor-Acceptor (D-A) or Donor-Acceptor-Donor (D-A-D) architectures, enabling the labeling of biomolecules such as estrone and tyrosine.