Related Experiment Video
Updated: Jul 14, 2026

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
The refocused INADEQUATE MAS NMR experiment in multiple spin-systems: interpreting observed correlation peaks and
Sylvian Cadars1, Julien Sein, Luminita Duma
1Laboratoire de Chimie (UMR 5182 CNRS/ENS Lyon), Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France.
Abstract:
The robustness of the refocused INADEQUATE MAS NMR pulse sequence for probing through-bond connectivities has been demonstrated in a large range of solid-state applications. This pulse sequence nevertheless suffers from artifacts when applied to multispin systems, e.g. uniformly labeled (13)C solids, which distort the lineshapes and can potentially result in misleading correlation peaks. In this paper, we present a detailed account that combines product-operator analysis, numerical simulations and experiments of the behavior of a three-spin system during the refocused INADEQUATE pulse sequence. The origin of undesired anti-phase contributions to the spectral lineshapes are described, and we show that they do not interfere with the observation of long-range correlations (e.g. two-bond (13)C-(13)C correlations). The suppression of undesired contributions to the refocused INADEQUATE spectra is shown to require the removal of zero-quantum coherences within a z-filter. A method is proposed to eliminate zero-quantum coherences through dephasing by heteronuclear dipolar couplings, which leads to pure in-phase spectra.
Related Concept Videos
NMR Spectrometers: Resolution and Error Correction
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...
2D NMR: Overview of Homonuclear Correlation Techniques
COSY90 is the standard two-dimensional (2D) COSY experiment that...
2D NMR: Overview of Heteronuclear Correlation Techniques
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
