Analisis AIM y NBO del enlace de hidrógeno aromático C-H...pi en el complejo C2H2/C6H6

VALLEJOS, MARGARITA; PERUCHENA, NELIDA

FACENA

Facultad de Ciencias Exactas y Naturales y Agrimensura UNNE

Año: 2007 vol. XXII p. 43 - 63

0325-4216

In the present work the topology of the charge density in C2H2/C6H6 complex, as a consequence of the weak C-H¡Kƒà interaction, is studied within the framework of the Density Functional Theory and the Atoms in Molecules Theory. The key electronic effects such as the redistribution of the charge density, en both fragments are presented and discussed. The results are obtained at B3LYP and MP2/6-31++G** level theory. In addition, the average atomic properties are determined on all atoms and their changes are analyzed. Unexpectedly, the acidic hydrogen atom shows a augment of the atomic volume in the complex. The Natural Bond Orbital (NBO) analysis revealed the transfer of 2,76me. from C6H6 to C2H2. The dominant part (44,7%) of this transfer goes into the ƒã*Caa-Haa but a similar amount is transferred to the two ƒà*Caa-Ca in C2H2.2H2/C6H6 complex, as a consequence of the weak C-H¡Kƒà interaction, is studied within the framework of the Density Functional Theory and the Atoms in Molecules Theory. The key electronic effects such as the redistribution of the charge density, en both fragments are presented and discussed. The results are obtained at B3LYP and MP2/6-31++G** level theory. In addition, the average atomic properties are determined on all atoms and their changes are analyzed. Unexpectedly, the acidic hydrogen atom shows a augment of the atomic volume in the complex. The Natural Bond Orbital (NBO) analysis revealed the transfer of 2,76me. from C6H6 to C2H2. The dominant part (44,7%) of this transfer goes into the ƒã*Caa-Haa but a similar amount is transferred to the two ƒà*Caa-Ca in C2H2.