Research output: Contribution to journal › Article › peer-review
Estimation of the contribution of vibronic interaction to the isotope effect on the nuclear magnetic shielding constant of a hydrogen bridge. / Golubev, N. S.; Tolstoi, P. M.; Shchepkin, D. N.
In: Russian Journal of General Chemistry, Vol. 76, No. 8, 01.08.2006, p. 1183-1190.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Estimation of the contribution of vibronic interaction to the isotope effect on the nuclear magnetic shielding constant of a hydrogen bridge
AU - Golubev, N. S.
AU - Tolstoi, P. M.
AU - Shchepkin, D. N.
PY - 2006/8/1
Y1 - 2006/8/1
N2 - A nonadiabatic correction to the H/D isotope effect on the constant of electronic magnetic shielding of a nucleus was estimated within the framework of the first-order perturbation theory. The procedure consists in the ab initio calculation of frequencies and relative intensities in the vibronic spectrum for H and D forms of a molecule taking into account only the transitions allowed in the magnetic-dipole approximation. With the elementary assumptions (case of Herzberg vibronic interaction), the semiquantitative estimation of adiabatic (geometrical) and nonadiabatic contributions to the H/D isotope effect on the 15N shielding constant of a complex with the HF-pyridine hydrogen bond was carried out. These two contributions to the isotope effect are comparable in the order of magnitude, at least for unsaturated molecules with low-lying excited electronic states. A correct solution to the problem requires ab initio calculation that is not based on the Born-Oppenheimer approximation.
AB - A nonadiabatic correction to the H/D isotope effect on the constant of electronic magnetic shielding of a nucleus was estimated within the framework of the first-order perturbation theory. The procedure consists in the ab initio calculation of frequencies and relative intensities in the vibronic spectrum for H and D forms of a molecule taking into account only the transitions allowed in the magnetic-dipole approximation. With the elementary assumptions (case of Herzberg vibronic interaction), the semiquantitative estimation of adiabatic (geometrical) and nonadiabatic contributions to the H/D isotope effect on the 15N shielding constant of a complex with the HF-pyridine hydrogen bond was carried out. These two contributions to the isotope effect are comparable in the order of magnitude, at least for unsaturated molecules with low-lying excited electronic states. A correct solution to the problem requires ab initio calculation that is not based on the Born-Oppenheimer approximation.
UR - http://www.scopus.com/inward/record.url?scp=33749394230&partnerID=8YFLogxK
U2 - 10.1134/S1070363206080019
DO - 10.1134/S1070363206080019
M3 - Article
AN - SCOPUS:33749394230
VL - 76
SP - 1183
EP - 1190
JO - Russian Journal of General Chemistry
JF - Russian Journal of General Chemistry
SN - 1070-3632
IS - 8
ER -
ID: 43112600