Achieving the Full Phase Space of Inorganic Natural Products and Beyond in Nanocrystal Synthesis

大自然，通过地质学，创造了一系列令人鼓舞的晶体，这些晶体具有广泛的特性（颜色、孔隙度和机械强度等）。不同类型的晶体的独特性质不仅是它们的化学组成的结果，而且是组成原子的精确和特殊排列的结果。作为纳米级晶体（尺寸仅为一根头发宽度的1/1000倍），这些不同的特性可能会带来深远的应用，如地球上丰富而活跃的工业催化剂、新的癌症治疗方法、磁性存储介质、更好的电池和廉价高效的太阳能电池板。在这一切成为可能之前，必须首先找到在纳米尺度上合成这些晶体的途径，因为极端的地质条件在化学实验室或工业设施中是不容易复制的。范德比尔特大学珍妮特·麦克唐纳教授的研究小组试图了解如何控制纳米级岩石中原子的精确位置。实验的目的是研究有机分子和金属原子发生反应时发生了什么，以及如何控制这些纳米级岩石中原子的精确位置。最终目标是制造出地质学所能制造的晶体的所有相，并可能设计和制备出具有新相的晶体。该项目还研究了小块氧化铁颜料的表面是如何与花岗岩表面结合在一起的，这些岩石画是美国和加拿大土著人Anishinaabe的耐久岩石画。这里的目标是重新发现失落的岩石艺术技术，并将其归还给Anishinaabe。该项目支持培训高中、本科和研究生水平的研究人员。已经建立的和新的联系鼓励Anishinaabe的研究人员参与研究。具体来说，该项目使用含有硫和硒原子的有机分子库作为前体，以获得由这些材料制成的各种晶体。一项广泛的，全面的和系统的研究相控制合成铁，钴，镍和铜硫系纳米晶体正在进行。利用有机硫族化合物文库将动力学速率与分解机制在相测定中的作用分离开来。鉴定了有机反应产物，以破译有机硫族化合物在金属上的分解机制，并推断这些机制对相控制的影响。在第二个目标中，有机硒醇和二硒化物化学促进了过渡金属硫属化合物的多型选择。利用纳米晶体反应的原位溶液1H和77Se核磁共振谱来了解有机硫族化合物化学如何影响纳米晶体合成中的多型性。在最后的推动力，赤铁矿颜料粘附二氧化硅的研究在不同的应用条件下精确控制使用实验室化学品。将这些研究翻译成自然来源的材料如下。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nature, through geology, has created an inspiring array of crystals with a wide range of properties (color, porosity, and mechanical strength, etc.). The unique properties of different types of crystals are a result of not only their chemical compositions, but also the precise and specific arrangement of the constituent atoms. As nanosized crystals (of dimensions of only about 1/1000 times the width of a strand of hair), these diverse properties could lead to applications as far reaching as earth abundant and active industrial catalysts, new cancer treatments, magnetic storage media, better batteries, and inexpensive and efficient solar panels. Before any of this is possible, the routes to synthesize these crystals at the nanoscale must first be discovered because the extreme conditions of geology cannot be easily replicated in the chemistry laboratory or industrial facilities. The research group of Professor Janet Macdonald at Vanderbilt University seeks to understand how the precise placements of atoms in nano-sized rocks can be controlled. Experiments are designed to interrogate what happens to organic molecules and metal atoms when they react and how to control the precise placement of atoms in these nano-sized rocks. The ultimate goal is to make all the phases of crystals that geology does, and possibly be able to design and prepare crystals with new phases. The project also examines how the surfaces of small pieces of iron oxide pigments bind to granite surfaces in the remarkably durable rock paintings of the Anishinaabe, an indigenous people of the United States and Canada. The goal here is to rediscover the lost technique for rock art and return it to the Anishinaabe. The project supports the training of researchers in high school, undergraduate and graduate student levels. Established and new connections encourage Anishinaabe researchers to take part in the research. Specifically, this project uses libraries of organic molecules that contain sulfur and selenium atoms as precursors to obtain the diverse crystals made of these materials. A wide, sweeping and systematic study of the phase-controlled synthesis of iron, cobalt, nickel and copper chalcogenide nanocrystals is being performed. Libraries of organochalcogenides are employed to separate the roles of kinetic rates from the decomposition mechanisms in phase-determination. Organic reaction products are identified to decipher the mechanisms of decomposition of the organochalcogenides on the metals and deduce the impact of these mechanisms on phase control. In a second aim, organoselenol and diselenide chemistry facilitates polytypic selection in the transition metal chalcogenides. In situ solution 1H and 77Se NMR spectroscopy of nanocrystal reactions are used to understand how the organochalcogenide chemistry influences the polytypism in nanocrystal synthesis. In the final thrust, adherence of hematite pigments to silica is studied under varied application conditions precisely controlled using laboratory chemicals. Translation of these studies to naturally sourced materials follows.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.