We present in this paper the structure resolution of a fluorinated inorganic-organic compound - Zn 3Al 2F 12· [HAmTAZ] 6 - by SMARTER crystallography, i.e. by combining powder X-ray diffraction crystallography, NMR crystallography and chemical modelling of crystal (structure optimization and NMR parameter calculations). Such an approach is of particular interest for this class of fluorinated inorganic-organic compound materials since all the atoms have NMR accessible isotopes ( 1H, 13C, 15N, 19F, 27Al, 67Zn). In Zn 3Al 2F 12·[HAmTAZ] 6, 27Al and high-field 19F and 67Zn NMR give access to the inorganic framework while 1H, 13C and 15N NMR yield insights into the organic linkers. From these NMR experiments, parts of the integrant unit are determined and used as input data for the search of a structural model from the powder diffraction data. The optimization of the atomic positions and the calculations of NMR parameters ( 27Al and 67Zn quadrupolar parameters and 19F, 1H, 13C and 15N isotropic chemical shifts) are then performed using a density functional theory (DFT) based code. The good agreement between experimental and DFT-calculated NMR parameters validates the proposed optimized structure. The example of Zn 3Al 2F 12·[HAmTAZ] 6 shows that structural models can be obtained in fluorinated hybrids by SMARTER crystallography on a polycrystalline powder with an accuracy similar to those obtained from single-crystal X-ray diffraction data.
ASJC Scopus subject areas
- Inorganic Chemistry