title: The indirect through-space F-F coupling in peri-difluoronaphthalene: is it anisotropic?
abstract: The (1)H, (19)F and (13)C spectra have been obtained of a sample of peri-difluoronaphthalene dissolved in the nematic liquid crystalline solvent ZLI 1695. The (13)C satellite spectra from the six, single-(13)C isotopomers at natural abundance in both the (1)H and (19)F spectra were identified and analysed to yield a set of residual total, anisotropic spin-spin couplings, T(ij). This was achieved by first obtaining residual (13)C-(19)F and (13)C-(1)H couplings from a proton-encoded, (13)C detected, local field 2D spectrum. The 45 values of T(HH), T(HF) and T(CH) were used to obtain the structure of the molecule, and then to estimate whether there is a significant contribution from the component along the magnetic field, J, of the anisotropic, electron-mediated, spin-spin coupling tensors for (13)C-(19)F and (19)F-(19)F pairs. It is found that there is strong evidence for a significant contribution of J to T(FF) but not for the (13)C-(19)F pairs.
authors.affiliation: School of Chemistry, University of Southampton, Southampton, UKSO17 1BJ.
authors.forename: J W
authors.initials: JW
authors.lastname: Emsley
authors.forename: G
authors.initials: G
authors.lastname: De Luca
authors.forename: A
authors.initials: A
authors.lastname: Lesage
authors.forename: M
authors.initials: M
authors.lastname: Longeri
authors.forename: F B
authors.initials: FB
authors.lastname: Mallory
authors.forename: C W
authors.initials: CW
authors.lastname: Mallory