Photophysical properties of unsymmetric meso-substituted porphyrins synthesized via the Suzuki coupling reaction

A new family of porphyrins containing different groups in meso positions was synthesized by Suzuki coupling reaction of meso mono- and dibromo-diarylporphyrins with several boronate esters, catalyzed by palladium organometallic complexes. These procedures gave high yields of unsymmetric porphyrins bearing carboxylate anchoring groups, with enhanced absorptions in the red and showing no tendency for aggregation in toluene or THF solutions. Such properties are of interest for application in dye-sensitized solar cells.