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

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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.