Luminescent molecular solar concentrators made of multi-Bodipy dyes

The synthesis of photoactive arrays consisting of Bodipy scaffoldings is described. The synthetic strategy involved first the construction of functionalised modules, then the use of specific Knoevenagel reactions. Boron-protection is required to avoid self-condensation. Comparison of thienylBodipy dyes with their phenyl analogues showed them to be both less chemically stable and more weakly fluorescent. In the multichromophoric species, efficient cascade energy transfer occurs upon absorption in the highest energy unit. The redox activity of the mixed dyes is analysed in terms of the behaviour of specific reference compounds.