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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 halogen effect on the C-13 NMR chemical shift in substituted benzenes

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Author(s):
Viesser, Renan V. [1] ; Ducati, Lucas C. [2] ; Tormena, Claudio F. [1] ; Autschbach, Jochen [3]
Total Authors: 4
Affiliation:
[1] Univ Campinas UNICAMP, Inst Chem, POB 6154, BR-13081970 Campinas, SP - Brazil
[2] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
[3] Univ Buffalo State Univ New York, Dept Chem, Buffalo, NY 14260 - USA
Total Affiliations: 3
Document type: Journal article
Source: Physical Chemistry Chemical Physics; v. 20, n. 16, p. 11247-11259, APR 28 2018.
Web of Science Citations: 9
Abstract

Recent research {[}Chem. Sci., 2017, 8, 6570-6576] showed for R-substituted benzenes with R = NH2, NO2 that the substitution effects on the C-13 NMR chemical shifts are correlated with changes in the sigma-bonding framework and do not follow directly the electron-donating or -withdrawing effects on the pi orbitals. In the present work we extend the study to halogen ( X = F, Cl, Br or I) substituted R-benzenes. The effect of X and R groups on C-13 NMR chemical shifts in X-R-benzenes are investigated by density functional calculations and localized molecular orbital analyses. Deshielding effects caused by the X atom on the directly bonded carbon nucleus are observed for F and Cl derivatives due to a paramagnetic coupling between occupied p orbitals and unoccupied sigma{*}(C-X) antibonding orbitals. The SO coupling plays an important role in the carbon magnetic shielding of Br and I derivatives, as is well known, and the nature of X also modulates the C-13 paramagnetic shielding contributions. Overall, the X and R substituent effects are approximately additive. (AU)

FAPESP's process: 17/17750-3 - Solvent Effect in NMR Parameters by ab initio Molecular Dynamics
Grantee:Lucas Colucci Ducati
Support type: Regular Research Grants
FAPESP's process: 17/20890-1 - Evaluation of shielding and transmission mechanisms of 1H, 13C and 19F NMR
Grantee:Renan Vidal Viesser
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 15/08541-6 - Nuclear magnetic resonance spectroscopy: beyond molecular structure assignment
Grantee:Claudio Francisco Tormena
Support type: Research Projects - Thematic Grants
FAPESP's process: 15/20106-3 - Effects of donating and withdrawing electrons groups on 13C NMR shielding tensor in halo-benzenes derivatives
Grantee:Renan Vidal Viesser
Support type: Scholarships abroad - Research Internship - Doctorate
FAPESP's process: 14/21930-9 - Study of the solvent effect on the spin spin coupling constant 1JPt-Tl in heavy metal complexes by ab initio molecular dynamics
Grantee:Lucas Colucci Ducati
Support type: Scholarships abroad - Research
FAPESP's process: 13/03477-2 - DOSY methods for analyses of the complex mixtures
Grantee:Claudio Francisco Tormena
Support type: Regular Research Grants
FAPESP's process: 12/12414-1 - Relationship between molecular electronic structure and heavy atom effect on 13C NMR chemical shift
Grantee:Renan Vidal Viesser
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 11/17357-3 - Relationship between molecular electronic structure, NMR parameters and conformational stability
Grantee:Claudio Francisco Tormena
Support type: Regular Research Grants