Towards improved halogenated BODIPY photosensitizers: clues on structural designs and heavy atom substitution patterns

The singlet oxygen (O-1(2)) production quantum yield (Phi(Delta)) of 14 halogenated BODIPY dyes has been determined (0.01 < Phi(Delta) < 0.99). O-1(2) production and photostability have been evaluated considering the BODIPY structure, the substitution pattern, and the number and type of heavy atoms and quenching rate constants of O-1(2) by the sensitizer. In view of the experimental results and principal component analysis (PCA), guidelines for an improved design of efficient and photostable halo-BODIPY sensitizers are proposed.