Synthesis Characterization And Reactivity Studies Of Novel Metalloporphyrin And Metalloisoporphyrin Complexes

Abstract

Isoporphyrin is a tetrapyrrolic macrocycle with three sp2-hybridized and one sp3-hybridized meso-carbon atom. On account of their unique electronic, redox characteristics and structural flexibility they show diverse applications. These include the ability to bind metal ions and have potential as sensors, catalysts, etc. Their ability to absorb light and generate reactive oxygen species upon excitation suggests them as a possible photosensitizer for targeted cancer therapy. Iron porphyrin often functions as a prosthetic group in biological systems. Their metal-binding capability allows them to participate in redox reactions, mimicking the action of metabolites or metalloproteins like hemoglobins, myoglobins, cytochromes, and peroxidase. Porphyrin and isoporphyrin systems also act as photocatalysts for the degradation of organic pollutants by leveraging their binding properties. Their tunable properties can be engineered to achieve high selectivity and sensitivity for these applications. newlineHigh-valent iron(IV)-oxo species are recognized as key reactive intermediates in the catalytic cycles of dioxygen activation and are isoelectronic with iron isoporphyrins. Iron isoporphyrins are believed to exhibit diverse catalytic activities. However, there is no report of detailed synthesis of iron isoporphyrin in the literature. Moreover, theoretical calculation to understand the reactivities of iron isoporphyrin was not performed. To understand the relevance of similar high valent iron porphyrin radicals isoporphyrins from three iron porphyrins Fe(TPP)Cl, 1b; [Fe(4-F-TPP)Cl], 2b and [Fe(3-OCH3-TPP)Cl], 3b were synthesized by treating 1b, 2b and 3b with ceric ammonium nitrate as chemical oxidant. The three novel iron(III) isoporphyrins synthesized were namely chloro[5-(methoxy)and#8722;5,10,15,20-tetrakis-5,21H-porphinato]iron(III) nitrate,1c, chloro[5-(methoxy)-5,10,15,20-tetrakis(4-fluoro)-5,21H-porphinato]iron(III) nitrate 2c and chloro[5-(methoxy)-5,10,15,20-tetrakis(3-methoxy)-5,21H-porphinato]iron(III) nitrate, 3c.