Solid-State NMR at 1.0 GHz: A World-Leading UK Facility to Deliver Advances in Chemistry, Biology and Materials Science

It is the structural arrangement and motion of molecules and ions that determine, e.g., the bulk properties of a material or the function of biomolecules. Therefore, the availability of state-of-the-art analytical infrastructure for probing atomic-level structure and dynamics is essential to enable advances across science. The power of solid-state Nuclear Magnetic Resonance (NMR) spectroscopy as such a probe is being increasingly demonstrated by applications to, e.g., materials for use as batteries or for radioactive waste encapsulation or capture of emitted carbon dioxide, pharmaceutical formulations, and protein complexes relevant to illness. Solid-state NMR is most sensitive to the local chemical structure (usually up to a few bond lengths) around a particular nucleus and is thus well suited to characterising the many important systems that lack periodic order, making it complementary to well-established diffraction techniques.
To extend the applicability of NMR, two key limiting factors must be addressed: sensitivity, i.e., the relative intensity of spectral peaks as compared to the noise level, and resolution, i.e., the linewidths of individual peaks that determine whether two close-together signals can be separately observed. Both sensitivity and resolution are much improved by performing NMR experiments at higher magnetic field; this proposal is to provide UK researchers with new solid-state NMR capability at a world-leading magnetic field strength of 23.5 Tesla, corresponding to a frequency for the 1H nucleus of 1.0 GHz. This builds on the very successful and well-established UK 850 MHz Solid-State NMR Facility, so as to create a combined 850 MHz and 1.0 GHz Facility whose sustainable ongoing and future operation will be based on the key factors that have enabled the success of the existing 850 MHz Facility: dedicated Facility Manager support and genuine nationwide buy-in achieved through oversight by a national executive and an independent time allocation procedure.
The resonance frequencies of different nuclear isotopes are well separated such that an NMR spectrum is specific to a particular chosen isotope. NMR experiments at 23.5 Tesla will make use of as much of the Periodic Table as possible. In solid-state NMR, the experiment is usually performed by physically rotating the sample around an axis inclined at the so-called magic angle of 54.7 degrees to the magnetic field. Nuclei are classified according to their so-called spin quantum number, I. For the two most important I = 1/2 nuclei, 1H and 13C, 1.0 GHz will much benefit so-called inverse (i.e., 1H) detection experiments, e.g., for pharmaceuticals and protein complexes, as well as 13C-13C correlation experiments, e.g., for investigating structure and dynamics in plant cell walls. High magnetic field is particularly important for the study of the over two thirds of NMR-active isotopes that possess an electric quadrupole moment, i.e., a non-spherical distribution of electric charge (I of 1 and above). The residual broadening (in the usual NMR scale of ppm) that remains in the magic-angle spinning experiment is inversely proportional to the magnetic field squared; as well as improving resolution, the concentration of the signal intensity into a narrower lineshape means a still greater sensitivity dependence on the magnetic field strength. Application examples include 14N and 35,37Cl for pharmaceuticals, and 25Mg, 45Sc and 71Ga in materials science.
A test of a powerful technique is its applicability to a wide range of problems. The new 1.0 GHz ultra-high magnetic field solid-state NMR facility will make possible experiments that provide unique information for applications across science, ranging from materials for catalysis, radioactive waste encapsulation, batteries, drug delivery, through gaining new understanding of geological processes, to the life sciences, e.g., plant cell walls, protein complexes, membrane proteins and bone structure.

By enabling new science across chemistry, materials science and biology, the new capability of a world-leading dedicated 1.0 GHz solid-state NMR facility will deliver impact for UK industry and wider society.
As evidenced by the existing 850 MHz solid-state NMR Facility and noting the vision to create a combined 1.0 GHz and 850 MHz dedicated solid-state NMR Facility, there will be direct use of this new Facility by UK industry. Specifically, the enhanced resolution and sensitivity achieved by the significant increase in the highest magnetic field strength for solid-state NMR in the UK will impact on the insight provided for systems of importance to, for example, the pharmaceutical (e.g., AstraZeneca and GlaxoSmithKline), oil/ fuel (e.g., Infineum and Sasol) and catalysis/ materials (e.g., BP, Johnson Matthey) industry. These companies will access the 1.0 GHz solid-state NMR infrastructure either via paid-for industrial contract research or through industry support of PhD student users of the Facility.
Moreover, the research carried out by academic users of the 1.0 GHz facility across the physical sciences and life sciences and in the remit of EPSRC, NERC, BBSRC and MRC will provide new insight into links between function and bulk properties and atomic-level structure and dynamics that will impact on many key society challenges. Considering specific examples: understanding of intermolecular interactions will lead to better pharmaceutical formulations for enhanced drug delivery; knowledge of the underlying chemistry will enable better energy materials and catalysts to be produced; insight into the molecular basis of plant cell wall properties impacts on recalcitrance, which hinders the use of plant biomass for renewable energy by inhibiting the conversion into fermentable sugars.