NMR at 1.2 GHz: A World-Leading UK Facility to Deliver Advances in Biology, Chemistry, and Materials Science

分子和离子的结构排列和运动决定了材料的体积性质或生物分子的功能。核磁共振（NMR）光谱技术对特定原子核周围的局部化学结构非常敏感，使其成为这种原子水平结构和动力学的有力探针。为了扩大核磁共振的适用性，必须解决两个关键的限制因素：灵敏度，即光谱峰相对于噪声水平的相对强度，以及分辨率，即单个峰的线宽，这决定了两个紧密相连的信号是否可以单独观察到。在高磁场条件下进行核磁共振实验，大大提高了灵敏度和分辨率；这项提议是为英国研究人员提供新的核磁共振能力，在世界领先的28.2 T磁场强度下，对应于1H核的频率为1.2 GHz。这建立在非常成功和完善的英国高场固态核磁共振NRF的基础上，基于使现有设施成功的关键因素，可持续的持续和未来的运行：专门的设施经理支持和真正的全国支持，通过国家行政部门的监督和独立的时间分配程序实现。28.2 T的核磁共振实验将尽可能多地利用元素周期表。样品的溶液态核磁共振最常应用于I = 1/2的原子核，包括1H， 13C和15N等关键同位素，这些原子核之间的相关性通常在1H上检测，以获得最佳灵敏度。最近在除1H以外的核上检测的实验，特别是13C和15N，已经获得了普及，因为可以实现高分辨率的重要系统，如本质上无序的蛋白质和大的生物分子包括复合物。高场溶液核磁共振特别有利于生物分子应用，例如，表征与疾病有关的系统的结构、动力学和相互作用，但也有利于小分子，特别是用于解决复杂的混合物。为了最大限度地提高可用的灵敏度，使用了所谓的低温探头，其中适当的部分保持非常冷。在固态核磁共振中，实验通常是通过绕一个与磁场以54.7度的所谓魔角倾斜的轴物理旋转样品来完成的。对于两个最重要的I = 1/2核，1H和13C， 1.2 GHz将非常有利于所谓的逆（即1H）检测实验，例如用于药物和蛋白质复合物，以及13C-13C相关实验，例如用于研究植物细胞壁的结构和动力学。高磁场对于研究三分之二以上具有电四极矩的核磁共振活性同位素特别重要，即电荷的非球形分布（I为1及以上）。魔角旋转实验中剩余的展宽（通常的核磁共振尺度为ppm）与磁场的平方成反比；在提高分辨率的同时，将信号强度集中到更窄的线形中意味着对磁场强度的更大的灵敏度依赖。应用实例包括医药领域的14N和35Cl，材料科学领域的25Mg， 71Ga和91Zr。对一项强大技术的检验是它对广泛问题的适用性。新的1.2 GHz超高磁场核磁共振设备将使实验成为可能，为跨科学应用提供独特的信息，范围从催化和光收集材料，电池，药物输送到生命科学，例如植物细胞壁，蛋白质复合物，膜蛋白和骨结构。

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. The technique of Nuclear Magnetic Resonance (NMR) spectroscopy is very sensitive to the local chemical structure around a particular nucleus, making it a powerful probe of such atomic-level structure and dynamics.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 NMR capability at a world-leading magnetic field strength of 28.2 T, corresponding to a frequency for the 1H nucleus of 1.2 GHz. This builds on the very successful and well-established UK High-Field Solid-State NMR NRF with sustainable ongoing and future operation based on the key factors that have enabled the success of the existing Facility: dedicated Facility Manager support and genuine nationwide buy-in achieved through oversight by a national executive and an independent time allocation procedure. NMR experiments at 28.2 T will make use of as much of the Periodic Table as possible. Nuclei are classified according to their so-called spin quantum number, I. Solution-state NMR on samples is most frequently applied to nuclei with I = 1/2 including such crucial isotopes as 1H, 13C and 15N with correlations between these nuclei traditionally detected on 1H for optimum sensitivity. More recently experiments detected on nuclei other than 1H, especially 13C and 15N, have gained in popularity because of the high resolution achievable for important systems such as intrinsically disordered proteins and large biomolecules including complexes. High field solution NMR is particularly beneficial for biomolecular applications, e.g. characterisation of structures, dynamics and interactions of systems implicated in diseases, but also small molecules, especially for resolving complex mixtures. To maximise the available sensitivity so called cryoprobes, where appropriate parts are kept very cold, are used.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. For the two most important I = 1/2 nuclei, 1H and 13C, 1.2 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 35Cl for pharmaceuticals, and 25Mg, 71Ga and 91Zr in materials science.A test of a powerful technique is its applicability to a wide range of problems. The new 1.2 GHz ultra-high magnetic field NMR facility will make possible experiments that provide unique information for applications across science, ranging from materials for catalysis and light harvesting, batteries, drug delivery, to the life sciences, e.g., plant cell walls, protein complexes, membrane proteins and bone structure.