Document Type : Regular Article
DEPARTMENT OF CHEMISTRY UNIVERSITY OF GUILAN
The structural and energetic characteristics of O3–H2O complexes have been investigated by means of B3LYP, MP2, MP4(SDTQ), CCSD(T) and QCISD(T) methods in conjunction with the AUG-cc-pVDZ and AUG-cc-pVTZ basis sets. Six conformers were found for the O3–H2O complex. Two different intermolecular interactions were expected to participate in the formation of complexes, namely conventional O∙∙∙H hydrogen bonding and O∙∙∙O interaction. The most stable structure is non-hydrogen bonded one with double O∙∙∙O interactions. The binding energies of the most stable complex corrected with BSSE and ZPE range from -5.99 to -12.20 kJ/mol at CCSD(T)/AUG-cc-pVTZ, QCISD(T)/AUG-cc-pVTZ and MP4(SDTQ)/AUG-cc-pVTZ high levels of theory. The equilibrium distance between centers of monomers (O3∙∙∙OH2) in the most stable complex at the CCSD(T)/AUG-cc-pVDZ and CCSD(T)/AUG-cc-pVTZ levels is 2.9451 and 2.9448 Å, respectively, in good agreement with the experimental value of 2.957 Å. The AIM calculations predict that the O∙∙∙O and O∙∙∙H interactions in O3–H2O complexes are electrostatic in nature.