The hydrogen bonded complexes of serine with water and with H2O2 (HP) have been completely investigated in the present study using second-order Møller-Plesset perturbation theory (MP2) and density functional theory (DFT) in order to determine their geometries, stabilization energies, vibrational frequenciesand electronic characteristics. The stabilization energies (∆EBSSE) span a range of − 2.76 to − 12.46 kcal/mol for 1:1 serine–water complexes and − 4.54 to − 12.73 kcal/mol for 1:1 serine–HP complexes. The ∆EBSSE values suggest that serine–HP complexes are more stable than serine–water complexes. For all the structures, complex formation results in elongation of N-H, O-H bonds and shortening of C-H bonds thereby showing the red-shift and blue-shift for the respective bonds. The structural, vibrational and electronic features are in accordance with the fact that HP is a better proton donor and water a better proton acceptor. The excellent relationship is obtained for the variation of ∆EBSSE values with the sum of the ρ values and the sum of laplacian at the BCPs for the HBs. The E (2) values are also in concordance with the calculated ∆EBSSE values.
Volume 134, 2022
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