ViscY nuclear magnetic resonance experiments for in situ chemical reaction monitoring under spin diffusion conditions.

Viscosity-enhanced spectroscopY (ViscY) offers a new way to analyze complex mixtures of time-varying composition. This communication reports the use of the viscous binary solvent DMSO-d6/water to induce NMR spin diffusion for in situ chemical reaction monitoring and real-time characterization of a 3-substituted 4-hydroxycoumarin derivative and its side-product.