Martini Francesca, Miah Habeeba K, Iuga Dinu, Geppi Marco, Titman Jeremy J
Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 3, 56124 Pisa, Italy.
School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
J Magn Reson. 2015 Oct;259:102-7. doi: 10.1016/j.jmr.2015.08.004. Epub 2015 Aug 18.
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.
本文描述了一种新的（19）F各向异性-各向同性位移相关实验，该实验在超快MAS条件下运行，在检测维度上能很好地分辨各向同性（19）F位移。新实验利用基于对称原理设计的重新耦合序列，在间接维度上重新引入（19）F化学位移各向异性。讨论了新实验适用的情况，并测量了聚（二氟乙烯）（PVDF）中的（19）F位移各向异性参数。此外，类似的重新耦合序列被证明可通过异核偶极相互作用有效地测量（1）H-（19）F距离。这通过应用于最近合成的含H-F氢键连接的一维链的锆膦酸盐材料得到了证明。
