MRI: Acquisition of a single crystal x-ray diffractometer at UC Merced

该奖项由主要研究仪器项目和化学研究仪器项目共同支持。加州大学默塞德分校正在获取一台双源单晶衍射仪，该衍射仪配备了铜和钼微焦点X射线源，迈克尔·芬德莱特教授及其同事丽贝卡·阿雷瓦洛、迈赫迈特·贝卡拉、詹妮弗·卢、马艳宝。通常，X射线衍射仪可以准确和精确地测量分子的完整三维结构，包括键距离和角度，并提供关于分子相对于邻近分子的空间排列的准确信息。这里描述的研究影响到许多领域，包括有机化学和无机化学、量子材料、材料化学、生物化学和催化。该仪器是该机构化学和生物化学专业本科生和研究生教学、科研和培训不可或缺的一部分。该设施作为一个地区性的XRD资源，通过与加州理工州立大学、CSU Sate East Bay、CSU State Stanislaus和西俄勒冈大学的研究人员积极合作，使加州中央山谷地区主要本科院校的学生和教职员工受益。该奖项旨在加强各级研究和教育。该仪器的研究重点是与表现出这种氧化还原行为的第一排金属元素的分子化合物的合成、分离、表征和反应活性。鉴定新的结构和成键一直是分子无机/有机金属化学的核心原则，而SCXRD是一种重要的表征工具。更有效地获取结晶学数据有助于简化结构类似物的开发，并指导基于旋转异构体评估的未来结构修改的设计。这是从新型亚硝基试剂发展转亚硝化反应的需要。X射线结晶学已经不仅仅是一种结构确定的工具--它是一种允许探索复杂分子的原子细节构象的技术。该仪器有助于开发新的计算工具，使结晶学数据能够进行“多构象”或“系综”建模，揭示大分子的隐藏替代构象，这通常对理解它们的功能至关重要。研究人员正在为SCXRD进行单晶选择和操作。对于材料和化学应用，干晶样品通常用于SCX射线衍射仪。对于生化和生物应用，在SC-X射线衍射仪测量过程中，样品可能停留在水溶液中。根据不同的应用，可使用声学或光学镊子。电解水是生产氢气的一种可行选择，有助于向脱碳经济过渡。X-射线衍射结果证实了催化材料的结构和纯度。作为固体润滑剂的2D材料的结构对其摩擦性能有着深远的影响。特别是，掺杂稀土离子的MoS_2表现出一种反常现象，即摩擦力与层数成反比，这违背了2D材料中摩擦力随着层数的增加而减小这一看似普遍的特性。利用该仪器进行结构测定对摩擦研究具有重要意义。SCX射线衍射谱是鉴定量子材料新相和新结构的重要表征工具。用单晶X射线衍射仪鉴定了合成的量子材料的晶体结构，并研究了引入异质相后其晶格和相的演化。金属卤化物钙钛矿(MHPS)作为高效单结太阳能电池的活性材料，在过去的十年里得到了迅速的发展。合成这些材料后的第一步也是最关键的一步是用SCX射线确定MHPS的晶格常数和晶体取向。如果没有这种表征，对这些样品进行的任何测量都保留了相当大的不确定性，并且不允许建立组成和光电行为之间的关联。金属有机骨架(MOF)由金属离子及其相互连接的有机配体组成，可以形成高度结晶的多孔结构，在形态和功能上都具有良好的可调性，这为探索前所未有的催化活性和选择性提供了一个有吸引力的平台。通过SCXRD对这些材料进行表征，可以了解催化活性部位的位置以及电催化是如何在这些部位发生的。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is jointly supported by the Major Research Instrumentation and the Chemistry Research Instrumentation Programs. The University of California - Merced is acquiring a dual-source single crystal diffractometer equipped with Cu and Mo microfocus X-ray sources, Professor Michael Findlater and colleagues Rebeca Arevalo, Mehmet Baykara, Jennifer Lu, Yanbao Ma. In general, an X-ray diffractometer allows accurate and precise measurements of the full three-dimensional structure of a molecule, including bond distances and angles, and provides accurate information about the spatial arrangement of a molecule relative to neighboring molecules. The studies described here impact many areas, including organic and inorganic chemistry, quantum materials, materials chemistry, biochemistry, and catalysis. This instrument is an integral part of teaching as well as research and research training of undergraduate and graduate students in chemistry and biochemistry at this institution. The facility serves as a regional XRD resource benefitting students and faculty from primarily undergraduate institutions within the Central Valley region of California with impacts through active collaborations with researchers California Polytechnic State University, CSU Sate East Bay, CSU State Stanislaus, and Western Oregon University.The award is aimed at enhancing research and education at all levels. Research enabled by the instrument is focused on the synthesis, isolation, characterization, and reactivity of molecular compounds with 1st-row metal elements which exhibit such redox behaviors. The identification of novel structure and bonding has long been a central tenet of molecular inorganic / organometallic chemistry, and SCXRD is an essential characterization tool. More efficient access to crystallographic data helps streamline the development of structural analogues and guide the design of future structural modifications based on rotamer assessment. This is needed of the development of transnitrosylation reactions from novel nitrosoreagents. X-ray crystallography has become much more than a tool for structure determination - it is a technique that allows the exploration of the conformational landscapes of complex molecules in atomic detail. The instrument helps develop new computational tools that enable "multi-conformer" or "ensemble" modeling of crystallographic data, revealing hidden alternative conformations of macromolecules, which is often critical for understanding their functions. Researchers are working on single crystal selection and manipulation for the SCXRD. For material and chemical applications, dry crystal specimen is commonly used in the SCXRD. For biochemical and biological applications, the specimen may stay in aqueous solutions during the SC-XRD measurements. Depending on different applications, either acoustic or optical tweezers are utilized. Water electrolysis is a viable option towards hydrogen production that facilitates the transition into a decarbonized economy. The structures and purity of catalytic materials are Confirmed by XRD results. The discovery that the structure of 2D materials used as solid lubricants has a profound effect on their frictional properties. In particular, MoS2 doped with Re ions exhibits an anomalous, i.e. inverse dependence of friction on number of layers in violation of the seemingly universal trait that friction decreases with increasing number of layers in 2D materials. Structure determination using the instrument is of prime importance for friction research. SCXRD is an essential characterization tool for identifying new phases and structures of quantum materials. SCXRD is used to identify the crystal structure of the synthesized quantum materials and study the evolution of their lattice and phase upon the introduction of heterogeneities. Metal halide perovskites (MHPs) have had a meteoric rise in the last decade as active materials in high-efficiency single junction solar cells. The first and most critical step following synthesis of these materials is SCXRD to ascertain lattice constants and crystal orientation of the MHPS. Without this characterization, any measurement done on these samples have retain considerable uncertainty and do not allow to establish the correlations between composition and optoelectronic behavior. Metal organic frameworks (MOFs), consisting of metal ions and their interlinking organic ligands, can be formed into a highly crystalline porous structure with excellent tunability in both morphology and functionality, which provides an attractive platform to explore unprecedented catalytic activity and selectivity. Characterization of these materials with SCXRD allow understanding where the catalytically active sites are located and how the electrocatalysis occurred on those sites.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.