Determination of NMR interaction parameters from double rotation NMR

Recent technique developments and applications of solid state NMR in characterising inorganic materials

“…This new generation of probes then allows concepts beyond just simply distinguishing sites on the basis of improved resolution to be introduced, providing additional structural information via the quantitative determination of anisotropic interactions. Examples of such experiments have been to use the sideband pattern intensity to detect dipolar coupling and CSA, as well as their relative orientations [16]. As an example the 17 O NMR spectrum of Lalanine ( Fig.…”

Ultra-high resolution 17O solid-state NMR spectroscopy of biomolecules: A comprehensive spectral analysis of monosodium L-glutamate·monohydrate

“…Oxygen, like carbon and nitrogen, is one of the core elements in bio/organic molecules and is involved in many structural and physiological functions. However the large quadrupole interaction in 17 O (spin-5/2) in bio/organic molecules, 6,7 combined with the low natural abundance (0.037 %), make it challenging to acquire high spectral resolution spectra that allow site-specific information to be unambiguously extracted from a multiple-site system. Different high-resolution NMR approaches for suppressing the quadrupole broadening have been developed: multiple-quantum (MQ) MAS 8,9 and later satellite-transition (ST) MAS 10,11 both of which rely on manipulation of spin-coherences by radio-frequency (rf) pulses; and double-rotation (DOR) 12,13 and dynamic-angle spinning (DAS) 12 rely on manipulation of the spatial tensors by sophisticated sample spinning.…”

“…Furthermore it has the advantage that the chemical shift anisotropy can be readily obtained. 17 With the advances in quadrupole NMR methodologies, a significant increase in 17 O NMR studies of bio/organic materials have been reported recently, 6,7 including a high-field 17 O solidstate NMR study of two large (64 and 80 kDa) protein-ligand complexes, 14 illustrating the potential of 17 O NMR spectroscopy toward large biological systems. In particular, recent demonstrations on 17 O DOR spectroscopy have reported ultra-high spectral resolution with linewidths of <1 ppm).…”

“…[15][16][17][18][19][20][21] It is worth noting that high-resolution 17 O NMR MQMAS and DOR have also been reported for many important inorganic materials. 5,[22][23][24] In comparison to inorganic materials, there are three major complications for 17 O solid-state NMR on bio/organic molecules: (1) the abundance of hydrogen in bio/organic molecules gives rise to significant dipolar broadening unless high power 1 H-decoupling is applied; (2) the quadrupole interaction is generally larger (7- 33 was used. The interaction between the valence electrons, and the nuclei and core electrons was described using ultrasoft pseudopotentials.…”

“…Calculations using the original X-ray crystal structure 25 gave unrealistically large forces for the X-ray determined hydrogen positions indicating that they were incorrect. For this reason, the 17 O NMR calculations were carried out on several structurally optimised MSG models: (1) a H-optimised structure for which only the hydrogen atoms were relaxed; (2) a O,H-optimised for which both oxygen and hydrogen atoms were relaxed; and (3) a fully optimised situation where all atoms are relaxed. In all cases, the structural optimisation originated from the X-ray crystal structure and the unit cell parameters were constrained to the original values found in the X-ray structure.…”