Artículos de revistas
The electronic origin of unusually large (n)J(FN) coupling constants in some fluoroximes
Registro en:
Magnetic Resonance In Chemistry. Wiley-blackwell, v. 51, n. 6, n. 334, n. 338, 2013.
0749-1581
WOS:000319969200003
10.1002/mrc.3950
Autor
Favaro, DC
Contreras, RH
Tormena, CF
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) 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. 51 6 334 338 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) CONICET [PIP 0369/10] UBATEC scientific programming Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) FAPESP [2010/10993-9] CONICET [PIP 0369/10]