Ultrafast transverse relaxation exchange NMR spectroscopy

Abstract

Molecular exchange between different physical or chemical environments occurs due to either diffusion or chemical transformation. Nuclear magnetic resonance (NMR) spectroscopy provides means of understanding the molecular exchange in a...

SPICY: a method for single scan rotating frame relaxometry

“…Furthermore, the 1D imaging version of SPICY could replace the CPMG readout part in multidimensional ultrafast NMR 65 or Laplace NMR (LNMR) experiments. 62,[66][67][68][69] The single scan approach also significantly facilitates the use of nuclear spin hyperpolarization techniques [70][71][72][73] to boost the sensitivity of the experiments by several orders of magnitude. For example, recently Qi et al 74 boosted T 2 relaxation dispersion measurements by dissolution dynamic nuclear polarization (dDNP) to study protein-ligand binding.…”

Ultrafast Nuclear Magnetic Resonance as a Tool to Detect Rapid Chemical Change in Solution

“…Examples include examining water movement in silica 66 and cement, 69,70 the monitoring of cheese ripening, 71 or monitoring the aggregation of ionic liquids. 68,72 Regardless of evident potential, these methods have not yet broadly been applied to studying chemical reactions, although there is one example using changes in T 2 and D to monitor binding of pyridine to an iridium catalyst and its metal-catalyzed deuteration (Figure 5d). 73 ■ COMBINING ULTRAFAST NMR WITH HYPERPOLARIZATION All NMR methods suffer from a low signal intensity.…”

“…Correlating the same parameters (e.g., T 2 - T 2 and D - D experiments) can give information about molecular exchange. For instance, water exchange between vesicles and free solution was probed by D - D diffusion exchange spectroscopy (DEXSY) ultrafast experiments and similarly exchange of chemical components of ionic liquids between its aggregates was studied by a T 2 - T 2 relaxation exchange spectroscopy (REXSY) approach to provide exchange rate parameters. These methods are excellent at detecting physical changes, in particular, the movement of molecules, typically water, into pores in macroscale structures.…”

“…As these changes are best revealed by changes in T 1 , T 2 , and D , they can be tracked using ultrafast Laplace NMR in a way that traditional 2D NMR cannot. Examples include examining water movement in silica and cement, , the monitoring of cheese ripening, or monitoring the aggregation of ionic liquids. , Regardless of evident potential, these methods have not yet broadly been applied to studying chemical reactions, although there is one example using changes in T 2 and D to monitor binding of pyridine to an iridium catalyst and its metal-catalyzed deuteration (Figure d) …”

Identifying Exchangeable Protons in a 1D NMR Spectrum by Spatially Selective Exchange‐Editing

“…[5] Related approaches which have recently attracted interest are relaxation exchange NMR spectroscopy (REXSY) and diffusion exchange NMR spectroscopy (DEXSY) which use difference in T 2 -relaxation rate and difference in diffusion coefficient as contrast respectively. [6][7][8][9] Exchange NMR spectroscopy and its variants are frequently used techniques and can be applied to a diverse set of problems including e. g. lithium ion dynamics in electrode materials, investigation of organic reaction mechanisms and studying protein dynamics. [10][11][12] All these methods take some time, either because of additional sample handling or the acquisition of two-dimensional datasets.…”