Solid-state NMR of exotic nuclei in inorganic, organometallic and composite materials

固态核磁共振（SSNMR）是一种在分子水平上表征固体材料结构和动力学的前沿技术。然而，元素周期表中有许多元素，由于其原子核的接受度低，传统上没有进行核磁共振研究。由于低共振频率，低天然丰度，广泛的核磁共振粉末模式和长松弛时间，所有这些都可以使常规核磁共振光谱的获取持续数天甚至数周，因此核被归类为不可接受的！我们建议开发和应用脉冲序列，结合特殊的硬件和高磁场，这将大大减少实验时间，使常规研究原子核周期表在一系列有趣的无机，有机金属和复合材料的SSNMR。使用这些方法，我们建议研究三大类材料，包括(i)茂金属，（ii）复合材料和（iii）纳米颗粒。茂金属因其不同的化学性质和在许多工业过程中的用途而引起极大的兴趣。SSNMR，计算化学和x射线衍射技术将用于研究茂金属的结构变异性，以及它们在聚合物的非均相催化中的作用。（ii）我们将研究两类复合材料：介孔金属氧化物（MMOs）和超分子固体。mmo具有可以物理或化学捕获各种分子的大孔隙，并且具有可以进行有趣的氧化还原化学的壁。后者是选择性吸附伯胺的银配位固体。核磁共振将用于探测宿主材料的结构，以及与客体分子的相互作用。（iii）纳米粒子（NPs）由于其独特的光学和电学特性以及作为宏观材料基石的用途，最近引起了很多兴奋。我们计划研究一系列不同组成的NPs的核心和表面，包括LaF3， CdS和CdSe和Au。

Solid-state nuclear magnetic resonance (SSNMR) is a technique that has come to the forefront for characterizing structure and dynamics in solid materials at the molecular level.  However, there are many elements in the periodic table that have traditionally not been subject to NMR investigation, due to the low receptivity of their nuclei.  Nuclei are classified as unreceptive due to low resonance frequencies, low natural abundances, broad NMR powder patterns and long relaxation times, all of which can make the acquisition of a routine NMR spectrum last for days or even weeks!  We are proposing to develop and apply pulse sequences, in combination with special hardware and high magnetic fields which will greatly reduce experiment times, to enable the routine investigation of nuclei across the periodic table in a series of interesting inorganic, organometallic and composite materials with SSNMR. Using these methodologies, we are proposing to investigate three major classes of materials, including (i) metallocenes, (ii) composite materials and (iii) nanoparticles.  (i) Metallocenes are of great interest for their diverse chemistry and use in many industrial processes.  SSNMR, computational chemistry and X-ray diffraction techniques will be used to study the structural variability of metallocenes, as well as their function in heterogeneous catalysis of polymers.  (ii) We will study two types of composite materials: mesoporous metal oxides (MMOs) and supramolecular solids.  MMOs have large pores that can physically or chemically trap a variety of molecules, and have walls with which interesting redox chemistry can be conducted.  The latter are silver coordination solids which selectively adsorb primary amines.  NMR will be used to probe the structures of the host materials, as well as interactions with the guest molecules.  (iii) Nanoparticles (NPs) have recently generated much excitement, due to their unique optical and electrical properties and utility as building blocks for macroscopic materials.  We plan to study the cores and surfaces of a series of NPs of different compositions, including LaF3, CdS and CdSe and Au.