DINAMIX • Laboratoire CEISAM // CEISAM Institute

In order to describe, understand, and eventually control chemical reactions, scientists need to know what is happening in reaction mixtures.

Nuclear magnetic resonance (NMR) is the chemist’s most powerful tool to "see" which molecules are in a sample. However, the available options are typically a comprehensive picture on a completed reaction, and partial snapshots throughout the reaction. Using concepts derived from magnetic resonance imaging (MRI) and recent instrumentation, we are developing methods to provide a more complete picture of solution mixtures that evolve in time.

Chemical samples often come as solution mixtures. While advanced analytical methods exist for samples at equilibrium, the information on components and their interactions that may be accessed for out-of-equilibrium mixtures is much more limited. These include, for example, reaction mixtures in chemical synthesis and catalysis, as well as biochemical enzymatic reactions. The DINAMIX project aim at providing additional molecular-level information on out-of-equilibrium mixtures.

The project relies on diffusion nuclear magnetic resonance (NMR) spectroscopy, a powerful method that separates the spectra of mixtures’ components and identifies interactions, in correlation with structural insight provided by NMR observables. A spatial parallelisation is used to approach that makes it possible to acquire data in less than a second, instead of several minutes with conventional methods. This also has the potential to boost the power of hyperpolarisation methods such as dissolution dynamic nuclear polarisation (D-DNP) for mixtures analysis.

D-DNP indeed provides NMR sensitivity enhancements of up to 4 orders of magnitude, which however last only for a short time in solution. The methods developed will be used for applications in reaction monitoring in catalytic organic synthesis and biochemistry.

Publications

Online reaction monitoring by single-scan 2D NMR under flow conditions (link)
Corentin JACQUEMMOZ, François GIRAUD, Jean-Nicolas DUMEZ.

Here we show that time series of single-scan ultrafast 2D NMR (UF2DNMR) spectra can be collected to monitor solution mixtures that circulate in a flow unit at high field.

SUMMIT ERC - Online reaction monitoring by single-scan 2D NMR under flow conditions

Interleaved spatial/spectral encoding in ultrafast 2D NMR spectroscopy (link)
Bertrand Plainchont, Patrick Giraudeau, Jean-Nicolas Dumez

We analyze and further develop the strategy of using spatial/spectral pulses for spatial encoding, and introduce the concept of interleaving in excitation space, to address drawback of UF2DNMR.

Application and methodology of dissolution dynamic nuclear polarization in physical, chemical and biological contexts (link)
Sami Jannin, Jean-Nicolas Dumez, Patrick Giraudeau, Dennis Kurzbach

This perspectives article highlights possible avenues for developments and applications of d-DNP in biochemical and physicochemical studies.

Hyperpolarized NMR Metabolomics at Natural 13C Abundance (link)
Arnab Dey, Benoît Charrier, Estelle Martineau, Catherine Deborde, Elodie Gandriau, Annick Moing, Daniel Jacob, Dmitry Eshchenko, Marc Schnell, Roberto Melzi, Dennis Kurzbach, Morgan Ceillier, Quentin Chappuis, Samuel F. Cousin, James G. Kempf, Sami Jannin, Jean-Nicolas Dumez,
and Patrick Giraudeau

This article introduces a new approach, based on hyperpolarized ¹³C NMR at natural abundance, that circumvents the sensitivity drawback of ¹³C NMR for metabolomics.

Ultrafast diffusion-based unmixing of 1H NMR spectra (link)
Rituraj Mishra, Achille Marchand, Corentin Jacquemmoz, and Jean-Nicolas Dumez

We show that the NMR spectra of components in a mixture can be separated using 2D data acquired in less than one second, and an algorithm that is executed in just a few seconds.

Frequency-swept pulses for ultrafast spatially encoded NMR
Jean-Nicolas Dumez

This article describes the spatial encoding of relaxation, chemical shift and diffusion in a common framework and discusses directions for future developments.

ERC DINAMIX – Real-time diffusion NMR analysis of mixtures

In more details

Project team