INVESTIGADORES
AUCAR Gustavo Adolfo
artículos
Título:
Interaction energies and NMR indirect nuclear spin-spin coupling constant in linear HCN and HNC complexes
Autor/es:
P. F. PROVASI, G. A. AUCAR, M. SANCHEZ, I. ALKORTA, J. ELGUERO AND S. P. A. SAUER
Revista:
JOURNAL OF PHYSICAL CHEMISTRY A
Editorial:
ACS
Referencias:
Año: 2005 vol. 109 p. 6555 - 6564
ISSN:
1089-5639
Resumen:
The cooperativity effects on both the electronic energy and NMR indirect nuclear spin-spin coupling constants J of the linear complexes (HCN)n and (HNC)n (n=1-6) are discussed. The geometries of the complexes were optimized at the MP2 level by using the cc-pVTZ basis sets. The spin-spin coupling constants were calculated at the level of the second-order polarization propagator approximation with use of the local dense basis set scheme based on the cc-pVTZ-J basis sets. We find strong correlations in the patterns of different properties such as interactoin energy, hydrogen bond distances, and spin-spin coupling constants for both series of compounds. The intramolecular spin-spin couplings are with two exceptions dominated by the Fermi contact (FC) mechanism, while the FC term is the only nonvanishing contribution for the intermolecular couplings. The latter do not follow the Dirac vector model and are important only between nearest neighbors.