RUI: CAS: Solvent-Free Synthesis of Transition Metal Halide Clusters

在化学系化学合成计划的支持下，奥特宾大学的迪恩·约翰斯顿教授将开发新的合成路线，以取代过渡金属卤化物簇合物材料，这些材料在生物成像、液晶和光学器件、催化、氧气传感和作为X射线造影剂方面具有潜在的应用前景。这类簇合物具有很强的磷光性，并且具有独特的电化学性质，这使得这些簇合物具有广泛的应用前景。中心星系团的核心非常稳定，使其成为创建新的化学结构的理想构建块，这些化学结构将星系团单元连接起来形成链或三维网络。值得注意的是，目前制备改性簇合物的基于溶液的方法受到产品的反应性和溶解性的严重限制，限制了可以产生和分离的材料的类型。该项目寻求克服与当前合成技术相关的障碍。该研究小组将使用金属簇盐的加热和机械研磨来制备具有潜在应用于光学器件和传感的新型材料。奥特宾大学的本科生将通过融入无机化学实验室的暑期研究经验和活动参与到这个项目中，在独立研究和无机材料的合成和表征方面获得宝贵的经验。这些研究经验将补充基本科学学者计划的活动，这是一个由NSF支持的学术、联合课程和非学术活动计划，旨在提高科学、技术、工程和数学(STEM)的保留率和毕业率。该研究项目旨在制备金属团簇合成子，用作新分子和材料的构建块，并允许精确控制团簇材料的连接性和维度。在所有已知的金属卤化物簇衍生物中，超过95%是同质的，这表明使用基于溶液的合成路线进行选择性配体取代是困难的。约翰斯顿研究小组将制备金属卤化物簇盐，其中阳离子被选择与阴离子簇反应，使用电荷平衡和阳离子的性质来控制反应的化学计量比。反应将在没有溶剂的情况下通过热或机械力化学方法启动，从而避免因溶剂干扰或溶解性问题而产生的复杂情况。将使用热重分析、原位拉曼光谱以及粉末和单晶X射线衍射法对反应和产物进行分析。这项研究的结果有望为无机团簇化学领域的研究人员提供合成工具和途径，以制备新的团簇材料。这一奖项反映了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。

With the support of the Chemical Synthesis program in the Division of Chemistry, Professor Dean Johnston of Otterbein University will develop new synthetic routes to substituted transition metal halide cluster materials that have potential future applications in bioimaging, liquid crystal and optical devices, catalysis, oxygen sensing, and as X-ray contrast agents. This family of clusters is strongly phosphorescent and has unique electrochemical properties, making the clusters potentially useful for a wide range of applications. The central cluster core is very stable, making it an ideal building block for the creation of new chemical constructs that link cluster units to form chains or three-dimensional networks. It is important to note that current solution-based methods for preparing modified clusters are severely limited by the reactivity and solubility of the products, restricting the types of materials that can be generated and isolated. This project seeks to overcome obstacles associated with current synthetic techniques. The research team will use thermal heating and mechanical grinding of metal cluster salts to prepare novel materials with potential applications for optical devices and sensing. Undergraduate students at Otterbein University will engage with this project through summer research experiences and activities integrated into the Inorganic Chemistry laboratory, gaining valuable experience in independent research and the synthesis and characterization of inorganic materials. These research experiences will complement the activities of the Cardinal Science Scholars Program, an NSF-supported program of academic, co-curricular, and non-academic activities demonstrated to increase retention and graduation in science, technology, engineering, and mathematics (STEM).This research project is directed toward the preparation of metal cluster synthons that are intended to serve as building blocks for new molecules and materials and to allow for precise control over connectivity and dimensionality of cluster materials. Greater than ninety-five percent of all known metal halide cluster derivatives are homoleptic, illustrating the difficulty in selective ligand substitution using solution-based synthetic routes. The Johnston research team will prepare metal halide cluster salts where the cation is selected to react with the anionic cluster, using charge balance and the properties of the cation to control the stoichiometry of the reaction. Reactions will be initiated by thermal or mechanochemical means in the absence of solvent, thereby avoiding complications from solvent interference or solubility issues. The reactions and products will be analyzed using thermogravimetric analysis, in-situ Raman spectroscopy, and powder and single-crystal X-ray diffraction methods. The results of this research are expected to provide researchers in the field of inorganic cluster chemistry with synthetic tools and pathways to prepare new cluster-based materials.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.