title: Recovering Invisible Signals by Two-Field NMR Spectroscopy.
abstract: Nuclear magnetic resonance (NMR) studies have benefited tremendously from the steady increase in the strength of magnetic fields. Spectacular improvements in both sensitivity and resolution have enabled the investigation of molecular systems of rising complexity. At very high fields, this progress may be jeopardized by line broadening, which is due to chemical exchange or relaxation by chemical shift anisotropy. In this work, we introduce a two-field NMR spectrometer designed for both excitation and observation of nuclear spins in two distinct magnetic fields in a single experiment. NMR spectra of several small molecules as well as a protein were obtained, with two dimensions acquired at vastly different magnetic fields. Resonances of exchanging groups that are broadened beyond recognition at high field can be sharpened to narrow peaks in the low-field dimension. Two-field NMR spectroscopy enables the measurement of chemical shifts at optimal fields and the study of molecular systems that suffer from internal dynamics, and opens new avenues for NMR spectroscopy at very high magnetic fields.
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, 75005, Paris, France.|CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Samuel F
authors.initials: SF
authors.lastname: Cousin
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, 75005, Paris, France.|CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Pavel
authors.initials: P
authors.lastname: Kadeřávek
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, 75005, Paris, France.|CNRS, UMR, 8640 Pasteur, 75005, Paris, France.
authors.forename: Baptiste
authors.initials: B
authors.lastname: Haddou
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, 75005, Paris, France.|CNRS, UMR 7203 LBM, 75005, Paris, France.|Laboratory of Chemical Physics, NIDDK, NIH, Bethesda, MD, 20892, USA.
authors.forename: Cyril
authors.initials: C
authors.lastname: Charlier
authors.affiliation: Bruker BioSpin GmbH, Silberstreifen 4, 76287, Rheinstetten, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Marquardsen
authors.affiliation: Bruker BioSpin, 34 rue de l'Industrie BP 10002, 67166, Wissembourg Cedex, France.
authors.forename: Jean-Max
authors.initials: JM
authors.lastname: Tyburn
authors.affiliation: Bruker BioSpin AG, Industriestrasse 26, 8117, Fällanden, Switzerland.
authors.forename: Pierre-Alain
authors.initials: PA
authors.lastname: Bovier
authors.affiliation: Bruker BioSpin GmbH, Silberstreifen 4, 76287, Rheinstetten, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Engelke
authors.affiliation: Bruker BioSpin, Billerica, MA, 01821, USA.
authors.forename: Werner
authors.initials: W
authors.lastname: Maas
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, 75005, Paris, France.|CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Bodenhausen
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France.|Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, 75005, Paris, France.|CNRS, UMR 7203 LBM, 75005, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Pelupessy
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure, PSL Research University, 24 rue Lhomond, 75005, Paris, France. Fabien.Ferrage@ens.fr.|Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, 75005, Paris, France. Fabien.Ferrage@ens.fr.|CNRS, UMR 7203 LBM, 75005, Paris, France. Fabien.Ferrage@ens.fr.
authors.forename: Fabien
authors.identifier: 0000-0002-4738-1723
authors.initials: F
authors.lastname: Ferrage
keywords: chemical exchange; high-field NMR spectroscopy; kinetics; low-field NMR spectroscopy; nuclear magnetic resonance