Synthesis of 1:2 molecular complexes between free base meso-tetraarylporphyrins and sulfur trioxide

Abstract

The interaction of meso-tetraarylporphyrins, H 2 T (4- X ) PP , with sulfur trioxide pyridine complex ( SO 3. py ) in chloroform only produced 1:2 molecular complexes, [ H 2 T (4- X ) PP ( SO 3)2]. UV-vis, 1 H NMR, and FT-IR spectra, as well as elemental analysis, suggested pseudo tetrahedrally distorted porphyrin core structures with σ-bonding from two pyrrolenine nitrogen donors to the d orbital of sulfur in two SO 3 s and the occurrence of two hydrogen bonds between two pyrrolic NH and oxygens of sulfur trioxides from above and below the mean plane of the porphyrins.