β-(Ethynylbenzoic acid)-substituted push-pull porphyrins: DSSC dyes prepared by a direct palladium-catalyzed alkynylation reaction

The palladium-catalyzed oxidative alkynylation of β-borylated porphyrins allows for concise preparation of push-pull structured ethynylbenzoic acid porphyrin derivatives. The resulting β-singly- and doubly-substituted porphyrin dyes are regarded as isomeric derivatives of the corresponding meso-substituted reference systems, and were found to give rise to nearly equal power conversion efficiencies when analyzed in DSSCs.