Thermodynamic Study on Reaction of Tetra Sulfona to Phenyl Porphyrin Iron (II) Complex With Different Nitrogenous Ligands

Abstract

The binding characteristics of number of axial aliphatic amines ligands were studied with Fe(ll)TPPS4 complex in aqueous solutions at hiqh PHs > 12.5 . All formed low spin octahedral complexes . Electronic absorption , ΔH , ΔG , and ΔS of these complexes have been reported and Calculated . The Path way for the axial ligation on addition of ligand to Fe(ll)TPPS4 is shown in one step . Hill Plots used to obtain the formation constants ( KF) and ( n ) number of axial ligands bonded to the iron(ll) ion . It has been found low values of the KF for these ligands comparing to those recorded in organic solvents may be due to the polar solvent , and these values ( KF) more higher than that recorded for aromatic amine with the same complex and solvents due to steric effect of the size of porphyrin ring .