A theoretical structural analysis of the factors that affect (1)J(NH), (1h)J(NH) and (2h)J(NN) in N-H...N hydrogen-bonded complexes.
Calculations of (1)J(NH), (1h)J(NH) and (2h)J(NN) spin-spin coupling constants of 27 complexes presenting N-H...N hydrogen bonds have allowed to analyze these through hydrogen-bond coupling as a function of the hybridization of both nitrogen atoms and the charge (+1, 0, - 1) of the complex. The main conclusions are that the hybridization of N atom of the hydrogen bond donor is much more important than that of the hydrogen bond acceptor. Positive and negative charges (cationic and anionic complexes) exert opposite effects while the effect of the transition states 'proton-in-the-middle' is considerable.
Alkorta
Ibon
I
Instituto de Química Médica, CSIC, Juan de la Cierva, 3, E-28006 Madrid, Spain. ibon@iqm.csic.es
Blanco
Fernando
F
Elguero
José
J
D006859:Hydrogen / Q000737:chemistry*; D006860:Hydrogen Bonding; D009584:Nitrogen / Q000737:chemistry*
D006859:Hydrogen; D009584:Nitrogen