Theoretical studies on the interaction mechanisms between tetrachloro-p-benzoquinone and hydrogen peroxide

Abstract

A detailed knowledge of the initial complexes is crucial for the better understanding of the reaction mechanisms between tetrachloro-p-benzoquinone (TCBQ) and hydrogen peroxide (H2O2). In the present study, the interaction modes and interaction mechanisms between TCBQ and H2O2 in the absence and presence of one, two, and three water molecules have been systematically investigated employing the B3LYP/6-311++G** level of theory in combination with the atoms in molecules theory and natural bond orbital (NBO) method. It was found that the introduction of water molecules can influence the original interaction modes between TCBQ and H2O2 through the formation of the intermolecular H-bonds. The interaction energies between TCBQ and H2O2 range from −0.37 to −2.75 kcal/mol for four stable complexes, which are smaller than that of the interaction between H2O2 and water molecule. Further energy decomposition analyses suggest that the coupling interactions between TCBQ and H2O2 are predominated by the electrostatic interactions regardless of the presence or absence of water molecules. In addition, the significant heat released from the interaction process in the presence of water molecules is expected to be favorable for the following reactions involving the production of the hydroxyl radical.