TY - JOUR

T1 - NMR Chemical Shift of a Helium Atom as a Probe for Electronic Structure of FH, F-, (FHF)-, and FH2+

AU - Tupikina, E. Yu

AU - Efimova, A. A.

AU - Denisov, G. S.

AU - Tolstoy, P. M.

N1 - Funding Information: This work was supported by the RFBR grant 17-03-00497. The calculations were performed in the Computer Center of Saint-Petersburg University Research Park. Publisher Copyright: © 2017 American Chemical Society. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.

PY - 2017/12/21

Y1 - 2017/12/21

N2 - In this work, we present the first results of outer electronic shell visualization by using a 3He atom as a probe particle. As model objects we have chosen F-, FH, and FH2+ species, as well as the hydrogen-bonded complex FH···F- at various H···F- distances (3.0, 2.5, 2.0, and 1.5 Å and equilibrium at ca. 1.14 Å). The interaction energy of investigated objects with helium atom (CCSD/aug-cc-pVTZ) and helium atom chemical shift (B3LYP/pcS-2) surfaces were calculated, and their topological analysis was performed. For comparison, the results of standard quantum mechanical approaches to electronic shell visualization were presented (ESP, ELF, ED, δ2ED). We show that the Laplacian of helium chemical shift, δ2ÎHe, is sensitive to fluorine atom lone pair localization regions, and it can be used for the visualization of the outer electronic shell, which could be used to evaluate the proton accepting ability. The sensitivity of δ2ÎHe to lone pairs is preserved at distances as large as 2.0-2.5 Å from the fluorine nucleus (in comparison with the distance to ESP minima, located at 1.0-1.5 Å or maxima of ELF, which are as close as 0.6 Å to the fluorine nucleus).

AB - In this work, we present the first results of outer electronic shell visualization by using a 3He atom as a probe particle. As model objects we have chosen F-, FH, and FH2+ species, as well as the hydrogen-bonded complex FH···F- at various H···F- distances (3.0, 2.5, 2.0, and 1.5 Å and equilibrium at ca. 1.14 Å). The interaction energy of investigated objects with helium atom (CCSD/aug-cc-pVTZ) and helium atom chemical shift (B3LYP/pcS-2) surfaces were calculated, and their topological analysis was performed. For comparison, the results of standard quantum mechanical approaches to electronic shell visualization were presented (ESP, ELF, ED, δ2ED). We show that the Laplacian of helium chemical shift, δ2ÎHe, is sensitive to fluorine atom lone pair localization regions, and it can be used for the visualization of the outer electronic shell, which could be used to evaluate the proton accepting ability. The sensitivity of δ2ÎHe to lone pairs is preserved at distances as large as 2.0-2.5 Å from the fluorine nucleus (in comparison with the distance to ESP minima, located at 1.0-1.5 Å or maxima of ELF, which are as close as 0.6 Å to the fluorine nucleus).

UR - http://www.scopus.com/inward/record.url?scp=85037821302&partnerID=8YFLogxK

U2 - 10.1021/acs.jpca.7b10189

DO - 10.1021/acs.jpca.7b10189

M3 - Article

C2 - 29178803

AN - SCOPUS:85037821302

VL - 121

SP - 9654

EP - 9662

JO - Journal of Physical Chemistry B

JF - Journal of Physical Chemistry B

SN - 1520-6106

IS - 50

ER -