Theoretical treatment of IO-X (X = N 2 , CO, CO 2 , H 2 O) complexes

• Published in: Physical chemistry chemical physics : PCCP 2022-03, Vol.24 (12), p.7203-7213
• Main Authors: Marzouk, S, Ajili, Y, Ben El Hadj Rhouma, M, Ben Said, R, Hochlaf, M
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Chemical reactions; Chemical Sciences; Density functional theory; Iodine; Troposphere
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d1cp05536d

Iodine monoxide (IO) is an important component of the biogeochemical cycle of iodine. For instance, it is present in the troposphere, where it plays a crucial role in the physical chemical processes involving iodine containing compounds. Here, we present a theoretical study on a series of atmospherically relevant complexes of IO with N , CO, CO and H O, where their structural and spectroscopic properties and their interaction energies are computed. Calculations are carried out by means of post Hartree-Fock (RCCSD(T) and RMP2) methods and density functional theory DFT (PBE0 and M05-2X) based approaches with and without the inclusion of dispersion correction. After comparison to RCCSD(T), we highlight the good performance of M05-2X(+D3) DFT in describing the bonding between IO and X (X = N , CO, CO , H O). Moreover, we found that the IO-X (X = N , CO, CO , H O) complexes are formed by non-covalent interactions between the two monomers. In sum, we characterized two types of complexes: I-bonded and O-bonded, where the former is more stable. The atmospheric implications of the present findings are also discussed such as in the formation of the iodine oxide particles (IOPs).