Solid-State Dynamic Nuclear Polarization at 9.4 and 18.8 T from 100 K to Room TemperatureJournal of the American Chemical Society (2015)
Efficient dynamic nuclear polarization (DNP) in solids, which enables very high sensitivity NMR experiments, is currently limited to temperatures of around 100 K and below. Here we show how by choosing an adequate solvent, 1H cross effect DNP enhancements of over 80 can be obtained at 240 K. To achieve this we use the biradical TEKPol dissolved in a glassy phase ofortho-terphenyl (OTP). We study the solvent DNP enhancement of both TEKPol and BDPA in OTP in the range from 100 to 300 K at 9.4 and 18.8 T. Surprisingly, we find that the DNP enhancement decreases only relatively slowly for temperatures below the glass transition of OTP (Tg = 243 K), and 1H enhancements around 15–20 at ambient temperature can be observed. We use this to monitor molecular dynamic transitions in the pharmaceutically relevant solids Ambroxol and Ibuprofen.
Publication DateNovember 10, 2015
Citation InformationMoreno Lelli, Sachin R. Chaudhari, David Gajan, Gilles Casano, et al.. "Solid-State Dynamic Nuclear Polarization at 9.4 and 18.8 T from 100 K to Room Temperature" Journal of the American Chemical Society Vol. 137 Iss. 46 (2015) p. 14558 - 14561
Available at: http://works.bepress.com/aaron-rossini/1/