Beyond periodicity: probing disorder in crystalline materials by solid-state nuclear magnetic resonance spectroscopy

Abstract

We show that solid-state NMR can probe the structure of crystalline materials when disorder is present and, hence, this provides a method to extend the periodic-based description obtained by diffraction techniques. Reviewing some of our recently published results, we first address the issue of NMR sensitivity using wollastonite CaSiO 3 . We then consider the atomic scale structure of solid-solution in the system La 2 Si 2 O 7 -Y 2 Si 2 O 7 and finally examine the Al/Si substitution in gehlenite CaAl 2 SiO 7 . Those examples allow us to propose an extended structural description of materials based on the definition of chemical and/or structural local environments.

An XRD and NMR crystallographic investigation of the structure of 2,6-lutidinium hydrogen fumarate

“…20,21 It complements other techniques (generally XRD) to either facilitate structure determination, 9,16,[22][23][24] interrogate the nature of both weak and strong intermolecular interactions [25][26][27][28] or investigate the structure of localised disorder within systems. 29 NMR crystallography of organic systems benefits particularly from the intrinsic sensitivity of 1 H chemical shifts to local interactions. 30 In this work, NMR, XRD and DFT are combined and utilised to investigate the intermolecular interactions and stability of 2,6-lutidinium hydrogen fumarate.…”

Temperature effects in first-principles solid state calculations of the chemical shielding tensor made simple

“…Interestingly, NMR can be used to study systems which lack periodicity and it can probe light elements such as hydrogen, both of which are challenging to study with other structure determination techniques such as X-ray diffraction. 4 Experimental NMR spectra cannot usually be related to the underlying structure and dynamics in a straightforward manner. This difficulty can be addressed by theoretically predicting NMR spectra that may then be used in conjunction with experimental results to study the structure and dynamics of the systems of interest.…”

Thermal Dehydrofluorination of GaPO-34 Revealed by NMR Crystallography

“…In recent years, interest has grown in the use of strategies such as NMR crystallography and “SMARTER” crystallography, which combine information from NMR spectroscopy (and often first-principles calculations) with X-ray (or neutron) crystallography to provide an in-depth picture of both the local and long-range structure of a material, where these techniques could not individually have provided such information. − These approaches have been especially successful for microporous materials, ,− particularly with recent advances in both computational power and the accuracy and efficiency of calculations available. − In particular, we recently reported the application of this approach to GaPO-34A, a material that can be prepared from the same starting gel as GaPO-34, but which contains multiple levels of compositional, orientational, and dynamic disorder that could not have been revealed or understood by using a single characterization technique …”