High-resolution 2D NMR spectra in inhomogeneous fields based on intermolecular multiple-quantum coherences with efficient acquisition schemes

Fast high-resolution J-resolved correlation spectroscopy in inhomogeneous fields

“…Huang and co-workers proposed iZQC-COSY and iSQC-JRES pulse sequences to achieve 2D COSY and JRES in inhomogeneous fields [19]. Lin et al also designed two pulse sequences based on the intermolecular doublequantum filter HOMOGENIED sequence for high-resolution COSY and JRES spectra respectively [20]. Nevertheless, conventional three-dimensional acquisition protocols introduce additional evolution delay and thus consume hours to record the data.…”

Reconstruction of Self-Sparse 2D NMR Spectra from Undersampled Data in the Indirect Dimension

“…Besides the sampling patterns, some reconstruction algorithms have been employed to improve spectral quality, including maximum entropy [6,7], iterative CLEAN algorithm [8] and Bayesian reconstruction [9]. The sparse sampling was incorporated with intermolecular multiple-quantum coherences for high-resolution 2D NMR spectra in inhomogeneous fields [10]. …”

“…NMR spectra includes regions where no signals arise because of the discrete nature of chemical groups [17]. The reason we pay attention to self-sparse NMR spectra is that many NMR spectra of chemical substances fall in this type [3,10,16,17]. Based on the concept of sparsity and coherence in CS, we demonstrate that a wavelet transform is not necessary to sparsify the self-sparse NMR spectra or even worsens the reconstruction.…”