Institut de Chimie Moléculaire et des Matériaux d'Orsay

Laboratoire de RMN en milieu orienté - LRMN

 

 

Project gNMR (ANR 2011-JS08-009-01)


Duration : 54 months (2011 - 2016)
 
Project Coordinator : Nicolas Giraud (LRMN - Université Paris-Sud 11)
 
Participants : Denis Merlet (LRMN -Université Paris-Sud 11), Christie Aroulanda (LRMN - Université Paris-Sud 11), Jonathan Farjon (LRMN - CNRS), Jean-Michel Ouvrard (LRMN - CNRS), Jean-Pierre Baltaze (LRMN - CNRS), et David Bonnaffé (G2M - Université Paris-Sud 11)

Description of the project gNMR


 NMR spectroscopy has proved to be a unique tool for probing structure and dynamics in a wide range of molecular assemblies. Continuous methodological developments, combined with the breakthroughs which have been accomplished in probe and spectrometer hardwares have led to a variety of high-resolution experiments that have paved the way for an accurate measurement of large ensembles of spin interactions. These observables are particularly useful to constrain the most sophisticated simulations, allowing to describe complex chemical species and processes at an atomic level.
 
  Unfortunately, in most of the systems that are of interest to the scientific community nowadays, the size or the complexity of the molecular architecture which is probed often leads to overcrowded spectra whose resolution is too low to give access to their analytical content. Neither the use of very high field spectrometers, nor the development of pulse sequences that combine broadband and selective irradiations have allowed to fully address this problem.
 
  In this context, we have recently proposed to develop an original concept which consists in carrying out a parallel acquisition of different experiments using a single-receiver-coil system. We have successfully shown that this approach could be applied to run different selective echoes in different parts of an NMR sample, leading to a spin-spin coupling edition of the interaction network around a selected spin nucleus.
 
  Following up these encouraging results, the research proposal aims at providing NMR spectroscopists with a novel generation of correlation experiments based on a sample spatial frequency encoding.
 
 First, a set of simulation programs will be developed, that will target the evaluation of the NMR signal, based on the analytical calculation of the evolution of spin coherences, which results from a gradient encoded pulse sequence.
 
 Second, capitalizing on this theoretical tool, we will then focus on the methodological development of new, high-resolution correlation techniques inspired by this sample gradient encoding concept.
 
 Third, since gradient encoded spectroscopy is intrinsically less sensitive than standard NMR experiments, we will aim at exploring several techniques as potential alternatives to improve sensitivity.
 
 Our ultimate goal will be to apply the high-resolution sequences that will result from this work to address challenging systems such as enantiomeric mixtures dissolved in chiral liquid crystals.

Publications


Pitoux, D., Hu, Z., Plainchont, B., Merlet, D., Farjon, J., Bonnaffé, D. & Giraud, N.*
Magnetic Field Dependence Of Spatial Frequency Encoding NMR As Probed On An Oligosaccharide.
Magnetic Resonance in Chemistry, 53: 836-844 (2015)

Herbert Pucheta J.E., Pitoux, D., Grison, C.M., Robin, S., Merlet, D., Aitken, D.J., Giraud, N. & Farjon, J.*
Pushing The Limits Of Signal Resolution To Make Coupling Measurements Easier.
Chemical Communication, 51: 7939-7942 (2015)

Pitoux, D., Plainchont, B., Merlet, D., Hu, Z., Bonnaffé, D. Farjon, J., & Giraud, N.*
Fully Resolved NMR Correlation Spectroscopy.
Chemistry –A European Journal, 21: 9044-9047 (2015)

Giraud, N., Pitoux, D., Ouvrard, J.M. & Merlet, D.
Combining J-edited and Correlation Spectroscopies Within a Multi-Dimensional Spatial Frequency Encoding: Toward Fully Resolved 1H NMR Spectra
Chem. Eur. J., 19: 12221-12224 (2013)

Communications


Bonnafé, D.*, Hu, Z., Pitoux, D., Plainchont, B., Merlet, D. Farjon, J. & Giraud, N.
J-Edited NMR Spectroscopy Of Oligosaccharides : How To Extract Chemical Shifts And Scalar Couplings From Highly Crowded 1H Spectra
18th European Carbohydrate Symposium. Moscow (Russia), 2 - 6 août 2015

Plainchont, B.*, Pitoux, D., Ouvrard, J.M., Merlet, D. Farjon, J. & Giraud, N.
Gradient-Encoded NMR : From Theory To Practice
EUROMAR 2015. Prague (Czech Republic), 5 - 10 juillet 2015

Giraud, N.
Slice-Selective NMR : Toward Fully Resolved Correlation Spectroscopy
56th Experimental Nuclear Magnetic Resonance Conference, Pacific Grove, CA (USA), 19-24 avril 2015.

Pitoux, D.*, Farjon, J., Merlet, D. & Giraud, N.
Revisiting Correlation Spectra in NMR Spectroscopy : Some Recent Developments in the Field of Spatial Frequency Encoding
EUROMAR 2014. Zürich (Switzerland), 29 juin-3 juillet 2014

Giraud, N., Pitoux, D., Ouvrard, J.M. & Merlet, D.
Combination of J-edited and Correlation Spectroscopies within a Multi-dimensional Spatial Frequency Encoding
EUROMAR 2013. Hersonissos, Crête (Grêce), 30 juin-5 juillet 2013

Giraud, N.
Rapid Acquisition Techniques
2ème Ecole Thématique du GERM, Cargèse, Corse, 18-23 mars 2013

Giraud, N., Béguin, L., Ouvrard, J.M., Courtieu, J., & Merlet, D.
Faster Analysis Of Fully Coupled Spin Networks : A Sample Spatial Encoding Approach And Its Application To Enantiomeric Discrimination In Chiral Liquid Crystals
The 7th Alpine Conference on Solid-State NMR. Chamonix, Mont-Blanc, 11-15 septembre 2011

Links :

This project gNMR is supported by the French National Research Agency (ANR 2011 JCJC SIMI 8).