A New N-Channel Maximum Entropy Method in NMR for Automatic Reconstruction of “Decoupled Spectra” and J-Coupling Determination

Abstract

A new N-channel (or multichannel) deconvolution method of 1D and 2D NMR spectra is presented based on the Maximum Entropy method. In the general case of spectra exhibiting several lines of various fine structures, the method allows simultaneous deconvolution of all lines. While deconvolution is performed, determination of the values of the coupling constants is possible. Reconstruction of “decoupled” 1D and 2D spectra is also performed in a fully automated approach. The efficiency of the method is illustrated on experimental 1D and 2D spectra. The method has been developed in the GIFA software, a complete package for processing of NMR data available from the authors.

Modeling of NMR processing, toward efficient unattended processing of NMR experiments

“…However positive/negative spectral reconstruction is possible by using the multi-channel approach [31] (see Table 3 List of defined statergies 3D FT analysis t 1 t 2 t 3 Pre processing F 2 F 3 2D analysis (any 2D strategy) F 1 1D analysis (any 1D or partial 2D strategy) F 1 F 2 F 3 Post processing a This phase is actually implemented in several independent phases. Fig.…”

Application du traitement par entropie maximale aux données RMN multidimensionnelles ; cas de l'échantillonnage partiel

“…Ainsi, cette approche a été proposée pour augmenter la résolution des spectres et optimiser le rapport signal sur bruit [1][2][3][4][5], analyser et mesurer les structures de couplage [6][7][8], analyser les DOSY par transformée de Laplace Inverse [9], etc. Cette flexibilité permet aussi de se libé-rer des contraintes des protocoles rigides d'échantillon-nage des temps dans les expériences multidimensionnelles.…”

“…Pour une présentation plus complète, nous invitons le lecteur à se tourner vers la littérature [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

Dynamic NMR: combined use of 1D selective EXSY and complete lineshape analysis of spectra subjected to reference deconvolution and linear prediction or the maximum entropy method

“…13 15 and maximum entropy methods (MEM). 10 The 1D Selective EXSY 16,17 (1D SEXSY) spectra in both CDCl 3 and TCE solvents were measured with the standard Bruker program selno in the temperature range 299.6-321.6 K with a digital resolution of 0.046 Hz per point. The pre-pulse relaxation delay time D1 was 2s.…”

“…8) in order to avoid the shortcomings of the latter. 9,10 We applied the above strategy in studying the exchange behaviour of the erythro isomer of compound 1. 11,12 This compound is used as a model for acquiring rate constants and activation parameters of the restricted rotation around the amide C-N bond, comparing results from different experimental approaches.…”