The work reports first studied kinetics of complexation between copper and heterosubstituted porphyrins, namely 5,10,15,20-tetraphenyl-21-thiaporphyrin and 5,10,15,20-tetraphenyl-21-oxaporphyrin, as well as comparison with the structural analogue being tetraphenylporphyrin. Spectrophotometric titration allowed for determination of basicity constants characterizing heterosubstituted porphyrins in acetonitrile-perchloric acid. An increasing basicity in the porphyrin series: HSP < H2TPP < HOP for about four orders of magnitude is shown as expected to be accompanied with enhancing coordination ability of the ligands.
