SASSY NMR: Simultaneous Solid and Solution Spectroscopy

Abstract

Synergism between different phases gives rise to chemical, biological or environmental reactivity, thus it is increasingly important to study samples intact. Here, SASSY (SimultAneous Solid and Solution spec-troscopY) is introduced to simultaneously observe (and differentiate) all phases in multiphase samples using standard, solid-state NMR equipment. When monitoring processes, the traditional approach of studying solids and liquids sequentially, can lead to information in the non-observed phase being missed. SASSY solves this by observing the full range of materials, from crystalline solids, through gels, to pure liquids, at full sensitivity in every scan. Results are identical to running separate 13 C CP-MAS solid-state and 13 C solution-state experiments back-to-back but requires only a fraction of the spectrometer time. After its introduction, SASSY is applied to process monitoring and finally to detect all phases in a living freshwater shrimp. SASSY is simple to implement and thus should find application across all areas of research.

Biphasic NMR of Hyperpolarized Suspensions─Real-Time Monitoring of Solute-to-Solid Conversion to Watch Materials Grow

“…Many recent examples, e.g. , by Simpson and co-workers in the context of biological substrates or Leskes and co-workers in the context of lithium-ion batteries, further showcase the current interest in solid– or solution–liquid interfaces and NMR methods to access biphasic systems.…”

A Simple Device for Automated Mixing of Heterogeneous Solid‐Liquid Reactions During In‐Situ Monitoring by NMR Spectroscopy

“…[9,10] To avoid issues caused by differences in magnetic susceptibility, NMR measurements are usually performed on a single phase (solid [11,12] or liquid [1] ), however examples of simultaneous monitoring of heterogenous solidliquid mixtures have also been reported. [13][14] To avoid issues caused by poor mixing and magnetic inhomogeneity, heterogenous reactions are commonly monitored by sampling a batch reaction performed ex-situ, with the sample typically filtered to isolate a single phase. [1,15,16] Ex-situ monitoring techniques allow reactions to be studied under realistic conditions, including the use of mechanical stirring.…”

“…Large differences in susceptibility leads to localised magnetic inhomogeneity, resulting in broadened peaks unless techniques such as pure‐shift or SHARPER are applied to suppress these [9,10] . To avoid issues caused by differences in magnetic susceptibility, NMR measurements are usually performed on a single phase (solid [11,12] or liquid [1] ), however examples of simultaneous monitoring of heterogenous solid‐liquid mixtures have also been reported [13–14] …”

Rigid PN Cages as 3-Dimensional Building Blocks for Crystalline or Amorphous Networked Materials

“…75% of total integration) for the oxidized P(V) vertices. To confirm that the unusual spectroscopic features were not due to degradation during the drying and grinding steps used for sample preparation, a SASSY NMR experiment [12] was performed directly on the crude (wet and soft) gel, which closely matched the spectrum of the solid (Figure S33), indicating that no significant chemical or structural changes occur in the drying and griding process. Instead, we speculate that the additional steric bulk of the ethyl substituents renders the fourth oxidation more challenging for ethyl PN cage 11 than for the methyl PN cage 2, resulting in formation of a mixed oxidation state material 12 that is less networked than 10.…”