Reaction of a Nitrosyl Complex of Co(II)-porphyrin with Hydrogen peroxide: Formation of a Porphyrin Radical Cation

Biplab Mondal; Bapan Samanta; Shankhadeep Saha; Riya Ghosh; Sayani Maity

doi:10.1002/asia.202401082

Reaction of a Nitrosyl Complex of Co(II)-porphyrin with Hydrogen peroxide: Formation of a Porphyrin Radical Cation

Chem Asian J. 2024 Nov 24:e202401082. doi: 10.1002/asia.202401082. Online ahead of print.

Authors

Biplab Mondal¹, Bapan Samanta², Shankhadeep Saha², Riya Ghosh², Sayani Maity²

Affiliations

¹ Indian Institute of Technology Guwahati, Dept. of Chemistry, Guwahati, 781039, Guwahati, INDIA.
² Indian Institute of Technology Guwahati, Chemistry, INDIA.

PMID: 39582035
DOI: 10.1002/asia.202401082

Abstract

A nitrosyl complex of Co(II)-porphyrinate, [CoII(TTMPP2-)(NO)], 1, [TTMPPH2 = 5,10,15,20-tetrakis(3,4,5-trimethoxyphenyl)porphyrin] having {Co(NO)}8 configuration has been synthesized and characterized spectroscopically as well as structurally. Complex 1 in dichloromethane:acetonitrile (1:4, v/v) solution at -40 °C reacts with hydrogen peroxide (H2O2) to result in the corresponding nitrite (NO2-) complex, [CoIII(TTMPP2-)(NO2-)], 2. The formation of a Co(III)-peroxynitrite intermediate is presumed in this reaction based on the characteristic phenol ring nitration test. From spectroscopic studies, formation of [CoIV=O] species followed by a Co(III)-porphyrin radical complex was observed during the course of the reaction.

Keywords: Nitric oxide, Cobalt nitrosyl, Peroxynitrite, Hydrogen peroxide, 2,4-di-tert-butylphenol.