Synthesis of new ionic intermediate sitting-atop complexes of free base meso-tetraarylporphyrin and phosphorus(V) chloride under solvent free conditions

The intermediate sitting-atop (i-SAT) complexes are metalloporphyrins in which the metal ion is bonded to fewer than four nitrogen atoms in the distorted porphyrin plane. The i-SAT complexes may be considered as models for the initial steps of the metallation of the macrocycles. The new ionic intermediate sitting-atop complexes of [PCl3(H2t(X)pp)]Cl2 containing phosphorus(V) was synthesized by reaction of PCl5 and meso-tetraarylporphyrins (H2t(X)pp) in solvent free conditions. The structure of the complexes was confirmed by (1H, 31P, 13C) NMR, FT-IR and UV–Vis spectroscopies, elemental analysis and electrical conductometry. These data proved that only two pyrrolenine nitrogen atoms of the porphyrin act as electron donors to one phosphorus(V) center and so two pyrrolic protons remained still on the macrocycle.