New trans-AB2C meso-substituted porphyrin amino acid esters with meso-substituents of tunable electron withdrawing power (B= mesityl, 4-C6H4F, 4-C6H4CF3, C6F5) were prepared as free amines 3a–3d, as N-acetylated derivatives Ac-3a–Ac-3d and corresponding zinc (II) complexes Zn-Ac-3a–Zn-Ac-3d. Several amide-linked bis (porphyrins) with a tunable electron density at each porphyrin site were obtained from the ...