Probing molecular dynamics with hyperpolarized ultrafast Laplace NMR using a low-field, single-sided magnet

Abstract

Ultrafast NMR measurements of diffusion and T2 relaxation reveal physical properties of samples and are compatible with hyperpolarization-based signal enhancement.

Production of highly concentrated and hyperpolarized metabolites within seconds in high and low magnetic fields

“…Low-field nuclear magnetic resonance (NMR) devices have become versatile tools for numerous applications including the investigations of materials, chemicals and for the in situ monitoring of chemical reactions. [1][2][3][4][5][6][7][8] The main advantage of low-field NMR is that the instruments can be made small for transportation to a location of interest. This has enabled NMR studies of objects that cannot necessarily be moved such as concrete constructions or coatings.…”

Ultrafast Laplace NMR to study metal–ligand interactions in reversible polarisation transfer from parahydrogen

“…In this work we use D-T 2 correlation experiments to measure D and T 2 for thermally polarised and SABRE-hyperpolarised pyridine. Pulse sequences for these D-T 2 correlation experiments have been reported elsewhere 17,21,36 and are summarised in Figure 2a. Briefly, they contain a PGSTE (pulsed field gradient stimulated echo) to achieve diffusion encoding which is followed by either a CPMG (Carr-Purcell-Meiboom-Gill) 41 or PROJECT (Periodic Refocusing of J Evolution by Coherence Transfer) 42 loop to encode T 2 relaxation.…”

“…Laplace NMR has been used to monitor chemical processes that result in changes in T 1 , T 2 or D, 54,55 although the technique is most typically applied to detection of bulk water at M concentrations. 36,56,57 Here, monitoring of chemical reactions involving species at tens of mM concentrations using ultrafast LNMR has been demonstrated. The advantage of using Laplace NMR to monitor these reactions is that the experiments used here took just 11 minutes and could provide information on both D and T 2 in the same measurement, whereas 1D CPMG and DOSY experiments took 36 mins each, providing a ca 6.5-fold time saving.…”

“…2 Therefore, hyperpolarised Laplace NMR can be highly beneficial to boost the signal intensity of single scan measurements. 2,20,21,36 For the first time we report the combination of Laplace NMR with the SABRE hyperpolarisation technique. Samples containing the active [Ir(H) 2 (IMes)(pyridine) 3 ]Cl SABRE catalyst were prepared as previously described and shaken manually with fresh 3 bar pH 2 for 10 seconds in a 65 G magnetic field before insertion into the 9.4 T spectrometer.…”

“…23,35 Single scan ultrafast LNMR is ideally suited for detection of hyperpolarised substances as the dataset can be recorded rapidly before relaxation of enhanced nuclear spin polarisation back to their Boltzmann-derived states. 17,20,21,36 In this work we use SABRE HP to provide enhanced 1 H NMR signals for the substrate pyridine, which we then use to collect single scan ultrafast LNMR experiments based on D-T 2 correlation. We have selected pyridine as it was one of the first molecules to be hyperpolarised using the SABRE technique in 2009 24 and since then has become one of the most studied substrates for SABRE HP.…”