Mechanism of initiation of the radical chain oxidation by molecular oxygen of hydroxymethylferrocene and its ethyl ether in organic solvents.

Autooxidation of ethoxymethylferrocene at 30–50°C promoted by the participation of strong and weak carboxylic acids HX is studied. The radical chain mechanism of the process is established, its kinetics characteristics are determined as well as the composition of the products among which other derivatives of ferrocene have been found. Based on the results of the present study and the earlier obtained data on oxidation of hydroxymethylferrocene a mechanism of initiation of the chains general for both metallocomplexes is suggested. It includes the formation of the intermediate CH2OR (R = H, C2H5) and its subsequent oxidative transformations leading to the formation of the peroxide radical C5H4Fe+·C5H4-CH2O2 · and ROH. The role of the approaching and orientation effect in transformations of this intermediate is discussed as well as the mechanism of the investigated reaction in general. [ABSTRACT FROM AUTHOR]