pyridinyl substituents, which arrange as a “bowl”. The nonseparable mixture of regioisomers III+IV is extremely well soluble in chloroform and, as tetramethylated tetracation, in water (≅10-1 M). It forms well-defined and water-soluble (5 × 10-4 M) heterodimers with ms-tetraphenylsulfonatoporphyrin as a free base, a zinc and a copper complex (Kdimer = 1.3 × 108 M-1). Dimers containing one copper porphyrinate