title: Solid-State Dynamic Nuclear Polarization at 9.4 and 18.8 T from 100 K to Room Temperature.
abstract: 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, (1)H 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 of ortho-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 (1)H 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.
authors.affiliation: Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , 69100 Villeurbanne, France.
authors.forename: Moreno
authors.initials: M
authors.lastname: Lelli
authors.affiliation: Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , 69100 Villeurbanne, France.
authors.forename: Sachin R
authors.initials: SR
authors.lastname: Chaudhari
authors.affiliation: Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , 69100 Villeurbanne, France.
authors.forename: David
authors.initials: D
authors.lastname: Gajan
authors.affiliation: Aix-Marseille Université, CNRS, ICR UMR 7273 , 13397 Marseille, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Casano
authors.affiliation: Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Rossini
authors.affiliation: Aix-Marseille Université, CNRS, ICR UMR 7273 , 13397 Marseille, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Ouari
authors.affiliation: Aix-Marseille Université, CNRS, ICR UMR 7273 , 13397 Marseille, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Tordo
authors.affiliation: Institut de Sciences Analytiques, Centre de RMN à Très Hauts Champs, Université de Lyon (CNRS/ENS Lyon/UCB Lyon 1) , 69100 Villeurbanne, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Lesage
authors.affiliation: Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Lyndon
authors.initials: L
authors.lastname: Emsley