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

例如，分子和离子的结构排列和运动决定了材料的整体性质或生物分子的功能。因此，为探测原子水平的结构和动力学而提供最先进的分析基础设施对于推动科学进步至关重要。固体核磁共振(核磁共振)光谱学作为这种探针的能力正日益被应用于例如用作电池的材料或用于封装或捕获排放的二氧化碳的放射性废物、药物配方和与疾病相关的蛋白质复合体。固体核磁共振对特定原子核周围的局部化学结构(通常最多几个键长)最敏感，因此非常适合于表征许多缺乏周期性的重要体系，使其成为公认的衍射技术的补充。为了扩大核磁共振的适用性，必须解决两个关键限制因素：灵敏度，即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，确定是否可以单独观察到两个接近的信号。通过在更高的磁场下进行核磁共振实验，灵敏度和分辨率都得到了极大的提高；这一提议是为了向英国研究人员提供新的固态核磁共振能力，磁场强度为23.5T，对应于1H原子核的频率为1.0 GHz。这建立在非常成功和成熟的英国850 MHz固态核磁共振设施的基础上，从而创建一个850 MHz和1.0 GHz的组合设施，其可持续的持续和未来的运营将基于使现有850 MHz设施取得成功的关键因素：专门的设施经理支持和通过国家执行人员的监督和独立的时间分配程序实现的真正的全国范围内的买入。不同核同位素的共振频率被很好地分开，使得核磁共振谱特定于特定的选定同位素。在23.5特斯拉的核磁共振实验将尽可能多地利用元素周期表。在固态核磁共振中，实验通常是通过将样品绕着与磁场成54.7度的所谓幻角倾斜的轴进行物理旋转。原子核根据它们所谓的自旋量子数I进行分类。对于两个最重要的I=1/2原子核，1H和13C，1.0 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体，以及13C-13C关联实验，例如用于研究植物细胞壁的结构和动力学。强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=1及以上)。魔角旋转实验中残留的剩余展宽(在通常的核磁共振标度中为ppm)与磁场的平方成反比；除了提高分辨率，将信号强度集中到更窄的线形中意味着对磁场强度的敏感性更高。应用的例子包括14N和35，37Cl用于医药，25 mg，45Sc和71Ga用于材料科学。对一项强大技术的测试是它对广泛问题的适用性。新的1.0 GHz超高磁场固态核磁共振设备将使实验成为可能，这些实验将为跨科学的应用提供独特的信息，范围从催化材料、放射性废物封装、电池、药物输送，通过对地质过程的新理解，到生命科学，例如植物细胞壁、蛋白质复合体、膜蛋白质和骨骼结构。

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. 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.