TY - JOUR
T1 - H-bond network in amino acid cocrystals with H 2O or H 2O 2. the DFT study of serine - H 2O and Serine - H 2O 2
AU - Vener, Mikhail V.
AU - Medvedev, Alexander G.
AU - Churakov, Andrei V.
AU - Prikhodchenko, Petr V.
AU - Tripol'Skaya, Tatiana A.
AU - Lev, Ovadia
PY - 2011/11/24
Y1 - 2011/11/24
N2 - The structure, IR spectrum, and H-bond network in the serine - H 2O and serine - H 2O 2 crystals were studied using DFT computations with periodic boundary conditions. Two different basis sets were used: the all-electron Gaussian-type orbital basis set and the plane wave basis set. Computed frequencies of the IR-active vibrations of the titled crystals are quite different in the range of 10 - 100 cm -1. Harmonic approximation fails to reproduce IR active bands in the 2500 - 2800 frequency region of serine - H 2O and serine - H 2O 2. The bands around 2500 and 2700 cm -1 do exist in the anharmonic IR spectra and are caused by the first overtone of the OH bending vibrations of H 2O and a combination vibration of the symmetric and asymmetric bendings of H 2O 2. The quantum-topological analysis of the crystalline electron density enables us to describe quantitatively the H-bond network. It is much more complex in the title crystals than in a serine crystal. Appearance of water leads to an increase of the energy of the amino acid - amino acid interactions, up to ∼50 kJ/mol. The energy of the amino acid - water H-bonds is ∼30 kJ/mol. The H 2O/H 2O 2 substitution does not change the H-bond network; however, the energy of the amino acid - H 2O 2 contacts increases up to 60 kJ/mol. This is caused by the fact that H 2O 2 is a much better proton donor than H 2O in the title crystals.
AB - The structure, IR spectrum, and H-bond network in the serine - H 2O and serine - H 2O 2 crystals were studied using DFT computations with periodic boundary conditions. Two different basis sets were used: the all-electron Gaussian-type orbital basis set and the plane wave basis set. Computed frequencies of the IR-active vibrations of the titled crystals are quite different in the range of 10 - 100 cm -1. Harmonic approximation fails to reproduce IR active bands in the 2500 - 2800 frequency region of serine - H 2O and serine - H 2O 2. The bands around 2500 and 2700 cm -1 do exist in the anharmonic IR spectra and are caused by the first overtone of the OH bending vibrations of H 2O and a combination vibration of the symmetric and asymmetric bendings of H 2O 2. The quantum-topological analysis of the crystalline electron density enables us to describe quantitatively the H-bond network. It is much more complex in the title crystals than in a serine crystal. Appearance of water leads to an increase of the energy of the amino acid - amino acid interactions, up to ∼50 kJ/mol. The energy of the amino acid - water H-bonds is ∼30 kJ/mol. The H 2O/H 2O 2 substitution does not change the H-bond network; however, the energy of the amino acid - H 2O 2 contacts increases up to 60 kJ/mol. This is caused by the fact that H 2O 2 is a much better proton donor than H 2O in the title crystals.
UR - http://www.scopus.com/inward/record.url?scp=81555200672&partnerID=8YFLogxK
U2 - 10.1021/jp207899z
DO - 10.1021/jp207899z
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C2 - 22004006
AN - SCOPUS:81555200672
SN - 1089-5639
VL - 115
SP - 13657
EP - 13663
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 46
ER -