TY - JOUR
T1 - The role of the CH/π weak interaction in the geometrical conformation
T2 - An aromatic acetamide derivative system as an example
AU - Ramírez, José Zeferino
AU - Vargas, Rubicelia
AU - Padilla-Martínez, Itzia I.
AU - Flores-Huerta, Anaid G.
AU - Garza, Jorge
PY - 2012/7
Y1 - 2012/7
N2 - In this work, three conformers of an aromatic amide derivative are theoretically analyzed. The theoretical methods used were based on the Kohn-Sham version of the density functional theory, considering three exchange-correlation functionals of different types: PBE, TPSS and B3LYP. The results obtained using these methods were compared to those obtained by the many-body perturbation theory to second order (MP2). All these methods where coupled with the 6-311++G(d,p) basis set. The X-ray structure was used as a starting point in the conformational search, as all the methods considered in this work had predicted that this structure would be the conformer with the highest energy, thus obtaining the first important result for this system. The second most important result discovered in this work refers to the large differences found in the predicted structures when applying DFT methods, as compared to the MP2 method. We attribute such differences to dispersion terms not included in the exchangecorrelation functionals considered; such a hypothesis is corroborated when a model system (stabilized by dispersion effects) is analyzed by applying the four theoretical methods. By incorporating dispersion effects with the exchange-correlation functional, we found they compared more favorably with the wave-function correlated method.
AB - In this work, three conformers of an aromatic amide derivative are theoretically analyzed. The theoretical methods used were based on the Kohn-Sham version of the density functional theory, considering three exchange-correlation functionals of different types: PBE, TPSS and B3LYP. The results obtained using these methods were compared to those obtained by the many-body perturbation theory to second order (MP2). All these methods where coupled with the 6-311++G(d,p) basis set. The X-ray structure was used as a starting point in the conformational search, as all the methods considered in this work had predicted that this structure would be the conformer with the highest energy, thus obtaining the first important result for this system. The second most important result discovered in this work refers to the large differences found in the predicted structures when applying DFT methods, as compared to the MP2 method. We attribute such differences to dispersion terms not included in the exchangecorrelation functionals considered; such a hypothesis is corroborated when a model system (stabilized by dispersion effects) is analyzed by applying the four theoretical methods. By incorporating dispersion effects with the exchange-correlation functional, we found they compared more favorably with the wave-function correlated method.
KW - Amide Derivatives
KW - DFT
KW - Dispersion Forces
KW - Grimme Correction
KW - Interaction
KW - MP2
KW - Weak Interactions
UR - http://www.scopus.com/inward/record.url?scp=84866651589&partnerID=8YFLogxK
M3 - Artículo
SN - 1870-249X
VL - 56
SP - 275
EP - 278
JO - Journal of the Mexican Chemical Society
JF - Journal of the Mexican Chemical Society
IS - 3
ER -