title: Measuring (19)F shift anisotropies and (1)H-(19)F dipolar interactions with ultrafast MAS NMR.
abstract: A new (19)F anisotropic-isotropic shift correlation experiment is described that operates with ultrafast MAS, resulting in good resolution of isotropic (19)F shifts in the detection dimension. The new experiment makes use of a recoupling sequence designed using symmetry principles that reintroduces the (19)F chemical shift anisotropy in the indirect dimension. The situations in which the new experiment is appropriate are discussed, and the (19)F shift anisotropy parameters in poly(difluoroethylene) (PVDF) are measured. In addition, similar recoupling sequences are shown to be effective for measuring (1)H-(19)F distances via the heteronuclear dipolar interaction. This is demonstrated by application to a recently synthesized zirconium phosphonate material that contains one-dimensional chains linked by H-F hydrogen bonds.
authors: Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 3, 56124 Pisa, Italy.
authors: Francesca
authors: F
authors: Martini
authors: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors: Habeeba K
authors: HK
authors: Miah
authors: UK 850 MHz Solid-state NMR Facility, Department of Physics, Millburn House, University of Warwick, Coventry CV4 7AL, UK.
authors: Dinu
authors: D
authors: Iuga
authors: Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 3, 56124 Pisa, Italy.
authors: Marco
authors: M
authors: Geppi
authors: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK. Electronic address: Jeremy.Titman@nottingham.ac.uk.
authors: Jeremy J
authors: JJ
authors: Titman
mesh_terms: D016880:Anisotropy; D005461:Fluorine / Q000737:chemistry*; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013696:Temperature; D015040:Zirconium / Q000737:chemistry
chemical_list: D007554:Isotopes; D005461:Fluorine; D015040:Zirconium
keywords: Anisotropic–isotropic shift correlation; Chemical shift anisotropy; Dipole-shift correlation; Heteronuclear dipolar coupling; Symmetry-based recoupling sequence; Ultrafast magic angle spinning