MRI: Acquisition of a High-Brilliance X-Ray Diffractometer for Fundamental Materials and Catalysis Research and Education at Howard University

该重大研究仪器（MRI）奖支持霍华德大学（一所历史上的黑人大学（HBCU））收购双源单晶X射线衍射仪。这种能力增强了霍华德大学的基础材料和催化研究，提供了将单晶X射线衍射（SC-XRD）分析的优势扩展到非结晶系统（如液体和无定形固体）、化学战剂分解、分析物检测、能量存储、化石能源转换、分子开关和存储器存储的应用机会。SC-XRD是可用于确定分子结构的最强大的技术之一。通过将聚焦的X射线束照射在晶体上，人们可以确定原子在分子中是如何连接的，这些原子在空间上是如何取向的，以及分子如何在晶体中聚集在一起。原子和分子排列的知识可以更好地理解分子的功能。这最终可以导致设计新材料，揭示生物体如何运作，并开发新的疗法来减轻人类的痛苦。产生的X射线束的强度允许快速分析具有挑战性的样品。这一工具建立并加强了现有的合作，并提高了中大西洋地区的研究能力。衍射仪还加强了霍华德大学的化学教育，并为学员提供了使用美国国家实验室先进设施的基础。这些活动激励了少数民族从事化学和晶体学研究，从而使国家学术界、政府和工业界的劳动力进一步多样化。此次收购的高亮度单晶X射线衍射仪具有多层光学元件的双微焦点Mo和Cu源，像素阵列探测器以无快门数据采集模式运行，以及温度控制系统，用于在80-400 K范围内的数据采集。双源配置允许快速收集高质量的衍射数据，以执行微晶和粉末样品的详细分析。高通量单色X射线允许弱衍射微晶的分析。受益于新文书的项目包括研究：（1）新型金属-有机骨架（MOFs）作为预成型的结晶基质，用于通过“结晶海绵法”进行的涉及非结晶化合物的分子结构解析/机理研究，（2）碳硼烷基配体设计，用于在诸如化学战剂（CWA）分解的应用中进行催化，（3）用于通过表面增强拉曼光谱进行分析物检测的各向异性纳米颗粒复合材料合成，（4）用于介电能量储存的嵌段共聚物强度，（5）用于通过大气压金属有机化学气相沉积产生氧化铁（II）核-壳微粒的配体合成（AP-MOCVD）用于化石能源转换过程，（6）用于开关和存储器存储的自旋交叉复合物的研究，和（7）设计催化顺序过程以衍生化杂环支架，用于产生新的自旋交叉材料和药物-该奖项反映了NSF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。

This Major Research Instrumentation (MRI) award supports the acquisition of a dual-source single-crystal x-ray diffractometer at Howard University, a Historically Black University (HBCU). This capability invigorates fundamental materials and catalysis research at Howard University, offering application opportunities in extending the benefits of single-crystal x-ray diffraction (SC-XRD) analysis to non-crystalline systems such as liquids and amorphous solids, decomposition of chemical warfare agents, analyte detection, energy storage, fossil energy conversion, molecular switches, and memory storage. SC-XRD is one of the most powerful techniques available to determine molecular structure. By shining a focused x-ray beam on a crystal, one can determine how atoms are connected in a molecule, how these atoms are spatially oriented, and how molecules are packed together in a crystal. Knowledge of atomic and molecular arrangement allows for a better understanding of how molecules function. This can ultimately lead to designing new materials, to revealing how living organisms operate, and to developing new therapeutics to alleviate human suffering. The strength of the generated x-ray beams permits rapid analysis of challenging samples. This instrument creates and fortifies existing collaborations and enhances research capability in the Mid-Atlantic region. The diffractometer also strengthens chemical education at Howard University and provides trainees a foundation to use advanced facilities at US national laboratories. These activities inspire underrepresented minorities to pursue chemistry and crystallography leading to further diversification of the national academic, governmental, and industrial workforce.The acquired high-brilliance single-crystal x-ray diffractometer features dual microfocus Mo and Cu sources with multilayer optics, a pixel array detector that operates in a shutterless data acquisition mode, and a temperature control system for data collection within a range of 80–400 K. The dual-source configuration allows for the rapid collection of high-quality diffraction data to perform detailed analyses of microcrystalline and powder samples. The high-flux monochromatic x-rays permits the analysis of weakly-diffracting microcrystals. The projects that benefit from the new instrument involves the study of: (1) novel metal-organic frameworks (MOFs) as preformed crystalline matrices for use in molecular structure elucidation / mechanistic investigations involving non-crystalline compounds through the “crystalline sponge method”, (2) carboranyl ligand design for catalysis in applications such as the decomposition of chemical warfare agents (CWA), (3) anisotropic nanoparticle composite synthesis for use in analyte detection through surface-enhanced Raman spectroscopy, (4) block copolymer strength for applications in dielectric energy storage, (5) ligand synthesis for iron(II) oxide core-shell microparticle generation through atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD) for application in fossil energy conversion processes, (6) investigation of spin crossover complexes for application in switches and memory storage, and (7) design of catalytic sequential processes to derivatize heterocyclic scaffolds for application in creating new spin crossover materials and drug-like molecules.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.