Electron interactions with hydrogen peroxide (H2O2)

Hydrogen peroxide (H2O2) is an important compound in several chemical processes that take place in outer space. As the molecule presents a considerable low theta(HOOH) internal rotational barrier regarding the interconversion to the trans structure, such conformation may be accessed when at the stratosphere. Hence, in this work, a systematic computational investigation on the electron interactions with H2O2 was performed through exploring the differential cross sections (DCS), integral cross sections (ICS), and momentum transfer cross sections (MTCS) for elastic scattering as well as the total cross sections (TCS) for different conformations of the target (theta(HOOH) = 119.8 degrees - experimental structure and theta(HOOH )= 180 degrees - trans) at a wide energy range (1-500 eV). To describe the electron-target interaction and solve the scattering equations, a molecular complex optical potential approach combined with Pade approximants was employed. At high energies, excellent agreement between present ICS (and also TCS) results and those determined in a previous work (through the use of a different methodology) was observed. In addition, ICS and MTCS were investigated extensively for H2O2. Interestingly, a resonance-like feature was observed in the ICS and MTCS of both conformations studied, which was assigned to the O-O bond. The resonance probed has sigma* character and is related to the B continuum (in the case of the experimental conformation) and B-u scattering symmetry (in trans conformation). More important, a shift of 1 eV was determined regarding the peak probed for trans conformation in comparison to that observed for the conformation with non-zero dipole moment, which may be used as an auxiliary for helping the identification of the presence of different H2O2 conformation in future experimental investigations. We encourage other investigations to be performed to verify (and to contribute to) the findings achieved in this work.