Stabilization of Free Radicals: its Importance in Reaction Kinetics

Abstract

A PREVIOUS paper¹ reported on a reaction of the radical chlorine oxide: enabling the transfer of chlorine oxide by means of addition of oxygen into the more stable chlorine trioxide and eventually, at a low temperature, into the stable chlorine hexoxide (Cl₂O₆). Similarly, the discussion² of the mechanism of the decomposition of ozone sensitized or catalysed by chlorine points to the fact that chlorine dioxide can also be considered as a chlorine atom stabilized by an oxygen molecule. The process Cl + O₂ = ClO₂ is exothermic to an extent of 1.5 kcal., and runs down practically without activation energy³. On examining the other cases in which the oxygen atom or molecule behaves in a similar manner, the cases of HO₂, NO and NO₂ radicals are striking. HO₂ and NO₂ are hydrogen and nitrogen atoms stabilized by an oxygen molecule, whereas NO is a stabilized complex from N· and O· and can also be transformed by addition of O₂ into NO₃.