Journal of Physical Chemistry A, Vol.113, No.41, 11051-11058, 2009
Computational Study on the Stacking Interaction in Catechol Complexes
The stability and electron density topology of catechol complexes (dimers and tetramer) were studied using the MPW1B95 functional. The QTAIM analysis shows that both dimers (face to face and C-H/pi one) display a different electronic origin. The formation of the former is accompanied by a significant change in the values of atomic electron dipole and quadrupole components, flattening the most diffuse part of the electron density distribution toward the molecular plane. A small electron population transfer is observed between catechol monomers connected by C-H/pi interactions, whose QTAIM characterization does not differ from that of a weak hydrogen bond. Cooperative effects in the tetramer on binding energies are small and negligible for bond properties and charge transfer. Nevertheless, they are significant oil atomic electron populations.