Abstract

We demonstrate that high field (9.4T) dynamic nuclear polarization (DNP) at cryogenic (similar to 100 K) sample temperatures enables the rapid acquisition of natural abundance H-1-H-2 cross-polarization magic angle spinning (CPMAS) solid-state NMR spectra of organic solids. Spectra were obtained by impregnating substrates with a solution of the stable DNP polarizing agent TEKPol in tetrachloroethane. Tetrachloroethane is a non-solvent for the solids, and the unmodified substrates are then polarized through spin diffusion. High quality natural abundance H-2 CPMAS spectra of histidine hydrochloride monohydrate, glycylglycine and theophylline were acquired in less than 2 h, providing direct access to hydrogen chemical shifts and quadrupolar couplings. The spectral resolution of the H-2 solid-state NMR spectra is comparable to that of H-1 spectra obtained with state of the art homonuclear decoupling techniques. (C) 2015 The Authors. Published by Elsevier Inc.

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