SYNTHESIS, CHARACTERIZATION AND CATALYTIC ACTIVITY OF MONONUCLEAR IRON(III) COMPLEXES TOWARDS HYDROCARBON OXIDATION AT ROOM TEMPERATURE

Non-heme mononuclear iron(III) complexes [Fe(L)Cl2]Cl (1) and [Fe(L )Cl2]Cl (2), where L = N,N-bis(2pyridylmethyl)-1,2-cyclohexanediamine and L= N,N-bis(2-pyridylmethyl)ethane-1,2-diamine, have been synthesized and characterized by means of elemental analysis and spectral methods. The catalytic properties of the complexes for the oxidation of saturated hydrocarbons have been investigated at room temperature using hydrogen peroxide (H2O2) and m-chloroperbenzoic acid (m-CPBA) as oxidants. Catalytic oxidation by environmentally benign H2O2 suggested a radical-based reaction pathway in the oxidation reaction. Further, total quenching of the oxidation process in the presence of “radical scavenger” 2,4,6-tri-t-butylphenol (TTBP) confirmed the involvement of radicals during the catalytic cycles. Significant enhancement in the selectivity towards alkane oxidation and regioselectivity in the oxidation of adamantane by replacement of H2O2 with m-CPBA as oxidant indicated the involvement of metal-based intermediate during catalytic oxidation reaction.