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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The electronic origin of unusually large (n)J(FN) coupling constants in some fluoroximes

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Author(s):
Favaro, Denize C. [1] ; Contreras, Ruben H. [2, 3] ; Tormena, Claudio F. [1]
Total Authors: 3
Affiliation:
[1] Univ Estadual Campinas, Inst Chem, BR-13084971 Sao Paulo - Brazil
[2] Consejo Nacl Invest Cient & Tecn, IFIBA, RA-1033 Buenos Aires, DF - Argentina
[3] Univ Buenos Aires, FCEyN, Dept Phys, Buenos Aires, DF - Argentina
Total Affiliations: 3
Document type: Journal article
Source: Magnetic Resonance in Chemistry; v. 51, n. 6, p. 334-338, JUN 2013.
Web of Science Citations: 6
Abstract

SOPPA(CCSD) calculations show that the FC term is the most important contribution to the through-space transmission of J(FN) coupling constants for the fluoroximes studied in this work. Because of the well-known behavior of FC term, a new rationalization for the experimental (TS)J(FN) SSCC is presented. It is mainly based on the overlapmatrix (S-ij) between fluorine and nitrogen lone pairs obtained from NBO analyses. An expression is proposed to take into account the influence of the electronic density (D-ij) between coupled nuclei as well as the s% character at the site of the coupling nuclei of bonds and non-bonding electron pairs involved in D-ij. In using this approach, a linear correlation between (TS)J(FN) versus D-ij is obtained. The most important aspect of this rationalization is related to the facility for understanding the behavior of some unusual experimental coupling constants. It is shown that, at least in this case, the electronic origin of the so-called through-space coupling is transmitted through to the overlap of orbitals on the coupled atoms, suggesting that, at least for these compounds, instead of through-space coupling, it should better be dubbed as `through overlapping orbital coupling'. Copyright (C) 2013 John Wiley \& Sons, Ltd. (AU)

FAPESP's process: 10/10993-9 - Transmission mechanism through space scalar coupling constants in NMR
Grantee:Claudio Francisco Tormena
Support Opportunities: Regular Research Grants