Hydrogen abstraction from poly(propylene) and poly(propylene oxide) by hydroxyl radicals: a computational quantum semi-empirical study

The reaction of hydrogen abstraction by hydroxyl radicals on two substrates (poly(propylene) and poly(propylene oxide)) was studied using three quantum semi-empirical methods (MNDO, AM1, PM3). The calculations were performed as a function of the site of abstraction (hydrogen atom on a secondary or tertiary carbon atom), and of the calculation method. In each case, we localised the transition state and showed that this transition state occurs early along the reaction coordinate. The results concerning the activation energies depend on the sites and the calculation methods. The calculated results were compared to experimental ones.