Three Generations of Cobalt Porphyrins as Catalysts in the Oxidation of Cycloalkanes

0512003 - ÚFCH JH 2020 RIV DE eng J - Journal Article
Pamin, K. - Tabor, Edyta - Gorecka, S. - Kubiak, W. - Rutkowska-Zbik, D. - Poltowicz, J.
Three Generations of Cobalt Porphyrins as Catalysts in the Oxidation of Cycloalkanes.
ChemSusChem. Roč. 12, č. 3 (2019), s. 684-691. ISSN 1864-5631. E-ISSN 1864-564X
Institutional support: RVO:61388955
Keywords : auxiliary basis-sets * oxygen * complexes * manganese * alkanes * metalloporphyrins * cytochrome-p-450 * approximation * hydrocarbons * autoxidation
OECD category: Physical chemistry
Impact factor: 7.962, year: 2019
Method of publishing: Open access

Three generations of cobalt porphyrins were synthesized, physicochemically characterized by FTIR and UV/Vis spectroscopy as well as cyclic voltammetry and applied as catalysts in the oxidation of cycloalkanes with atmospheric molecular oxygen under mild conditions. All examined catalysts were active in the tested reaction, and their catalytic activity varied with the nature and number of substituents on the porphyrin ring. Introduction of electron-withdrawing or electron-donating substituents at the porphyrin rings increases the activity of metalloporphyrin complexes. It was found, for the first time, that generation II cobalt porphyrins show higher activity in cycloalkane oxidation than cobalt porphyrins of generation III. The lower catalytic activity of generation III cobalt porphyrins can be attributed to the saddle-shaped deformation of the porphyrin macrocycle. DFT modeling of Co porphyrins and their interactions with molecular oxygen provided explanations for the observed effects. On the basis of prior reports and the obtained results, a reaction mechanism is proposed and discussed.
Permanent Link: http://hdl.handle.net/11104/0302226