Electron interactions with hydrogen peroxide (H₂O₂)

Highlights: • Integral cross sections (ICS) and momentum transfer cross sections (MTCS) were first ever determined at low energies for H₂O₂. • A resonance-like feature was observed in the ICS and MTCS of both (experimental and trans) conformations studied. • The feature presented has ${\sigma }^{\ast }$ character and was assigned to the O–O single bond. 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 (${\theta }_{\mathrm{HOOH}}=119.8$° - experimental structure and ${\theta }_{\mathrm{HOOH}}=180$° - 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 Padé 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 OO bond. The resonance probed has ${\sigma }^{\ast }$ 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.