Adsorption of Methyl Hydroperoxide (CH3OOH) on Water Ice. Theoretical Study with Systematic Assessment of Coordination Modes

The low-temperature interaction between methyl hydroperoxide CH3OOH (MHP) and the hexagonal water ice surface was studied using DFT (BLYP/6-31++G(d,p)) calculations. The structures, energies, and some thermodynamic properties of the molecular complexes between MHP and the water clusters (H2O)48, (H2O)56, (H2O)72 representing the surface fragments of the (0001), (101̅0), and (112̅0) crystallographic planes of the hexagonal oxygen lattice of the water ice Ih with proton ordering corresponding to Pisani’s P-ordered model were calculated. The various modes of coordination and intrusion were studied using the extended set (up to 192 points for each plane) of the structures optimized at the semiempirical (PM3) level. The validity of the surface models was verified by the stability of the results obtained in the cluster series (H2O)n, (n = 48, 72, 192, 216) at the semiempirical level as well as by DFT calculations of selected structures at the BLYP/6-311++G(2d,2p) level.