1H/15N NMR chemical shielding, dipolar15N,2H coupling and hydrogen bond geometry correlations in a novel series of hydrogen-bonded acid-base complexes of collidine with carboxylic acids
作者:Phillipe Lorente、Ilja G. Shenderovich、Nikolai S. Golubev、Gleb S. Denisov、Gerd Buntkowsky、Hans-Heinrich Limbach
DOI:10.1002/mrc.946
日期:2001.12
have been observed, where the proton is located closer to oxygen. For these complexes, the isotropic 1H and 15N chemical shifts and the 15N chemical shielding tensor elements were measured (the latter by lineshape simulation of the static powder spectra) as a function of the hydrogen bond geometry. For the deuterated analogs 1H/2H isotopeeffects on the isotropic 15N chemical shifts were obtained under
Geometries and Tautomerism of OHN Hydrogen Bonds in Aprotic Solution Probed by H/D Isotope Effects on <sup>13</sup>C NMR Chemical Shifts
作者:Peter M. Tolstoy、Jing Guo、Benjamin Koeppe、Nikolai S. Golubev、Gleb S. Denisov、Sergei N. Smirnov、Hans-Heinrich Limbach
DOI:10.1021/jp1027146
日期:2010.10.14
the analysis of the corresponding 1H chemical shifts, it was possible to distinguish between OHN hydrogenbonds exhibiting a single proton position and those exhibiting a fast proton tautomerism between molecular and zwitterionic forms. Using H-bond correlations, we relate the H/D isotopeeffects on the 13C chemical shifts of the carboxyl group with the OHN hydrogen bond geometries.