Quantum chemical study of hydrogen-bonded complexes of serine with water and H2O2

The hydrogen bonded complexes of serine with water and with (HP) have been completely investigated in the present study using second-order Moller-Plesset perturbation theory (MP2) and density functional theory (DFT) in order to determine their geometries, stabilization energies, vibrational frequencies and electronic characteristics. The stabilization energies ( 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 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 values with the sum of the values and the sum of laplacian at the BCPs for the HBs. The values are also in concordance with the calculated values. Synopsis Hydrogen-bonded serine-water and serine-Hydrogen Peroxide (HP) complexes have been extensively studied using quantum chemical methods. The nature of interactions exhibited by these complexes has been explored on the basis of analysis of geometrical data, stabilization energies, vibrational frequencies, AIM, NBO and SAPT studies.