Effects of pH and ionic strength on the structure and spectroscopic properties of Fe(III) complex porphyrin in aqueous solutions

Summary form only given. The porphyrin iron complexes are important components of nature involved in various biological processes. We report on the studies of the effect of pH and ionic strength on the equilibrium of different forms of the Fe(lII) complex of mesotetrakis(4-N-methyl-pyridiniomyl) porphyrin Fe(II)TmPyP or FeTMP in aqueous solutions by linear optical absorption, the Z-scan technique and EPR. The experimental results of Z-scan and electroparamagnetic resonance (EPR) are compared with semi-empirical quantum chemical calculations (ZINDO).