A Pure Shift-Based Nuclear Magnetic Resonance Method for In-Phase Three-Dimensional Diffusion-Ordered Spectroscopy.

Diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY) plays a vital role in mixture studies. However, its applications to complex mixture samples are generally limited by spectral congestion along the chemical shift domain caused by extensive coupling networks and abundant compounds. Herein, we develop the in-phase multidimensional DOSY strategy for complex mixture analyses by simultaneously revealing molecular self-diffusion behaviors and multiplet structures with optimal spectral resolution.

Diffusion Analysis on Complex Mixtures under Adverse Magnetic Field Conditions by Spatially-Selective Pure Shift-Based DOSY.

Diffusion-ordered NMR spectroscopy (DOSY) serves as a noninvasive spectroscopic method for studying intact mixtures and identifying individual components present in mixtures according to their diffusion behaviors. However, DOSY techniques generally fail to discriminate complex compositions which exhibit crowded or overlapped NMR signals, particularly under adverse magnetic field conditions. Herein, we exploit the spatially selective pure shift-based DOSY strategy to address this challenge by eliminating inhomogeneous line broadenings and extracting pure shift singlets, thereby expediting diffusion analyses on complex mixtures.

A pure shift and spin echo based approach for high-resolution diffusion-ordered NMR spectroscopy.

Diffusion-ordered NMR spectroscopy (DOSY) can be used for separating mixture components according to their individual diffusion behaviors, thus offering a powerful tool for the analysis of compound mixtures. However, conventional DOSY experiments generally encounter the problem of limited resolution in the spectral domain, particularly for applications to complex mixtures that contains crowed resonances in 1D NMR. In addition, chemical exchange effects, bringing about spurious component signals, pose another limitation for interpreting DOSY measurements.