CHEMISTRY OF HYDROTRIOXIDES - A COMPARATIVE ABINITIO STUDY OF THE EQUILIBRIUM STRUCTURES OF MONOMERIC AND DIMERIC HYDROTRIOXIDES (CH3OOOH, H3SIOOOH) AND HYDROPEROXIDES (CH3OOH, H3SIOOH) - RELATIVE BOND STRENGTHS IN AND THE GAS-PHASE ACIDITIES OF HYDROTRIOXIDES AND HYDROPEROXIDES

Ab initio calculations have been carried out to predict the equilibrium structures of monomeric and dimeric CH3OOOH, H3SiOOOH, CH3OOH, and H3SiOOH. The calculated relatively strong binding energies for the intermolecularly hydrogen-bonded cyclic dimers of the hydrotrioxides and hydroperoxides investigated (BE = 6-8 kcal/mol) support the belief that self-association is the characteristic structural feature of these species. Ab initio calculations of the theoretical acidities, defined as the energy differences between the energy minima for the neutral molecules and those for the corresponding anions, reveal the following order of the gas-phase acidities: H3SiOOOH > CH3OOOH > H3SiOOH > CH3OOH. The investigation of relative bond strengths indicates that the RO-OOH bonds in the hydrotrioxides are weaker than the ROO-OH bonds, supporting the predictions from the previous thermochemical and kinetic studies that the split into RO⋆ and ⋆OOHradicals is the lowest energy radical decomposition pathway available for these polyoxides. © 1990, American Chemical Society. All rights reserved.