Mechanism of Al(3+)-catalyzed oxidations of hydrocarbons: dramatic activation of H2O2 toward O-O homolysis in complex [Al(H2O)4(OOH)(H2O2)](2+) explains the formation of HO• radicals

Maxim L Kuznetsov; Yuriy N Kozlov; Dalmo Mandelli; Armando J L Pombeiro; Georgiy B Shul'pin

doi:10.1021/ic102476x

Mechanism of Al(3+)-catalyzed oxidations of hydrocarbons: dramatic activation of H2O2 toward O-O homolysis in complex [Al(H2O)4(OOH)(H2O2)](2+) explains the formation of HO• radicals

Inorg Chem. 2011 May 2;50(9):3996-4005. doi: 10.1021/ic102476x. Epub 2011 Apr 1.

Authors

Maxim L Kuznetsov¹, Yuriy N Kozlov, Dalmo Mandelli, Armando J L Pombeiro, Georgiy B Shul'pin

Affiliation

¹ Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, TU Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal. max@mail.ist.utl.pt

PMID: 21456552
DOI: 10.1021/ic102476x

Abstract

A radical mechanism of hydrocarbon oxidations with the environmentally friendly and cheap homogeneous nontransition metal system [Al(H(2)O)(6)](3+)/H(2)O(2)/MeCN-H(2)O was proposed for the first time on the basis of DFT calculations. A dramatic activation of H(2)O(2) toward homolysis in the key intermediate [Al(H(2)O)(4)(OOH)(H(2)O(2))](2+) due to the presence of the easily oxidizable OOH coligand provides, without a change of metal oxidation state, the generation of HO(•) radicals, which then oxidize hydrocarbons. Nonradical mechanisms of the olefin epoxidation with the same catalytic system were also investigated.