Characterisation of gas phase halide-acetone complexes with photoelectron spectroscopy and ab initio calculations

Photoelectron Spectroscopy and High-Level Ab Initio Calculations of the Iodide–Methylperoxy Radical Complex

“…45 The E stab value also serves as a good proxy to infer the strength of the electrostatic interaction as these interactions dominate the binding of anion van der Waals complexes. By this metric, the iodide−methylperoxy complex (E stab = 0.40 eV) is similarly bound compared to other iodide−molecule complexes, with values of 0.40, 0.41, 0.48, and 0.44/0.43 eV for 48 and 41,4941,49 respectively. also corresponds in mass to CH 3 IO 2 − ; however, experiments where they have been observed required addition of these solvent molecules to the gas mixture in similar quantities as the halide precursor.…”

“…Literature examples of O 2 – cluster formation via electric discharge and direct attachment of low-kinetic-energy electrons support the formation of the superoxide complex. − In the high m / z range (Figure b), a strong I – peak suggests that if any CH 3 OO is formed, complex formation by direct addition is also available. While previous work within the Wild Group has generated halide–molecule complexes readily in the gas phase by simple association, − the presence of a relatively intense O 2 – peak in the mass spectrum suggests that more complex dynamics may be present.…”

Hydrogen Bonding versus Halogen Bonding: Spectroscopic Investigation of Gas‐Phase Complexes Involving Bromide and Chloromethanes

“…Measuring the kinetic energy of the ejected electron gives the electron binding energy (e BE ), which can be used to determine the strength of a non-covalent interaction by comparing the binding energy of an anion-molecule complex to that of its respective bare anion. [50][51][52] Ab initio or density functional theory calculations represent methods of locating theoretical electronic structures of chemical systems. Such methods allow for the calculation of theoretical interaction energies, for example those that occur between molecule-molecule complexes, [53][54][55][56][57] or ion-molecule complexes, [58][59][60][61][62][63] based on the geometry of a chemical species.…”

“…In this technique photons interact with an anion species causing detachment of an electron. Measuring the kinetic energy of the ejected electron gives the electron binding energy (e BE ), which can be used to determine the strength of a non‐covalent interaction by comparing the binding energy of an anion‐molecule complex to that of its respective bare anion [50–52] …”