NMR in operando monitoring of mechanochemically accelerated sublimations

Solid-solid interactions in optically active materials lead to the phenomena of spontaneous enantioenrichment, with implications in prebiotic chemistry and materials purification. Herein, we report a setup that uses mechanochemistry to promote these interactions and which is coupled with the analytical power of nuclear magnetic resonance (NMR) to in operando monitor the resulting variation. The system is applied to the analysis of optically active species responding to cases of self-disproportionation of enantiomers (SDE) by sublimation. The fundamentals behind the observed phenomenon led to an advanced concept of enantiomers recognition based on selective sublimation. The work shows how mechanochemistry aids the acceleration of the naturally occurring phenomena and how the mechanical promotion of solvent-free solid interactions leads to a simultaneous control over the physicochemical properties of a material. In parallel, the study expands the field of monitoring in mechanochemistry by introducing the concept of continuous transfer and analysis of analytes outside the milling environment.