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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.)

NMR spin-spin coupling constants: bond angle dependence of the sign and magnitude of the vicinal (3)J(HF) coupling

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Viesser, Renan V. ; Ducati, Lucas C. ; Autschbach, Jochen ; Tormena, Claudio F.
Total Authors: 4
Document type: Journal article
Source: Physical Chemistry Chemical Physics; v. 18, n. 34, p. 24119-24128, SEP 14 2016.
Web of Science Citations: 4

The dependence of the magnitude and sign of (3)J(HFF) on the bond angle in fluoro-cycloalkene compounds is evaluated by electronic structure calculations using different levels of theory, viz. DFT, SOPPA(CCSD) and SOPPA(CC2). Localized molecular orbital contributions to (3)J(HFF) are analyzed to assess which orbitals are responsible for (3)J(HFF) and which are the most important coupling transmission mechanisms for each compound. Fluoro-ethylene is used as a model system to evaluate the dependence of the (3)J(HFF) coupling constant on the angle between the sigma(C alpha-F) and sigma(C alpha)'(-HF) vectors. Through-space and hyperconjugative transmission pathways and ring strain are identified as responsible for the opposite trend between (3)J(HFF) and bond angle, and for the negative signs obtained for the two molecules, respectively. One of the fluorine lone pairs, sigma(C alpha)'(-HF), sigma(C alpha-F), and sigma(C alpha)'(-C beta)' bonding orbitals and the sigma(C alpha-F){*} antibonding orbital are involved in the J-coupling pathways, according to analyses of pairwise-steric and hyperconjugative energies. (AU)

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