A hypervalent iodine secondary oxidant synthesized by photosensitized singlet oxygen: Synthesis, characterization and oxidative reactivity

Chemical scavenging of singlet oxygen by iodobenzene in the presence of (triethyleneglycol)monomethyl ether led to the formation of almost spherical nano-structured iodosylbenzene in water, water/acetonitrile and acetonitrile. To our knowledge, it is the first report on the direct aerobic photooxidative synthesis of iodosylbenzene. A polymer supported cationic porphyrin, nanoAmbSO(3)@H2TMPyP, was used as the photosensitizer. The nanoparticles, were characterized by various spectrophotometric and microscopic methods. The reactivity of the secondary oxidant for the oxidation of organic substrates was studied in the oxidation of methyl phenyl sulfide catalyzed by manganese meso-tetrakis(2-methylphenyl)por phyrin.The synthesis of the reactive secondary oxidant, PhIO, is suggested as an applicable strategy to overcome the problem of very short lifetime of singlet oxygen in organic solvents and water, which decreases the efficiency of singlet oxygen due to the involvement of the oxidant in unwanted physical and chemical quenching pathways.It is noteworthy that due to very short lifetime of singlet oxygen, most of the singlet oxygen produced in the presence of different photosensitizers is deactivated by other species to return to its triplet ground state by physical or non-productive chemical quenching. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study reported the chemical scavenging reaction of singlet oxygen by iodobenzene in the presence of (triethyleneglycol)monomethyl ether, resulting in the formation of almost spherical nano-structured iodosylbenzene in water, water/acetonitrile, and acetonitrile. By using a polymer supported cationic porphyrin as the photosensitizer, the oxidation of organic substrates was achieved. A strategy of synthesizing a reactive secondary oxidant was proposed to overcome the short lifetime of singlet oxygen in organic solvents and water.