title: Interaction energies and NMR indirect nuclear spin-spin coupling constants in linear HCN and HNC complexes.
abstract: 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 interaction 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.
authors.affiliation: Department of Physics, Northeastern University, Av. Libertad 5500, W 3404 AAS Corrientes, Argentina. patricio@unne.edu.ar
authors.forename: Patricio F
authors.initials: PF
authors.lastname: Provasi
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Aucar
authors.forename: Marina
authors.initials: M
authors.lastname: Sanchez
authors.forename: Ibon
authors.initials: I
authors.lastname: Alkorta
authors.forename: José
authors.initials: J
authors.lastname: Elguero
authors.forename: Stephan P A
authors.initials: SP
authors.lastname: Sauer
mesh_terms: D004583:Electrons; D006856:Hydrogen Cyanide / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy
chemical_list: D006856:Hydrogen Cyanide