CAREER: Cavity-Enforced Structure and Reactivity of High-Valent Iron Oxo, Nitrosyl, and Superoxo Complexes

职业：高价铁氧合、亚硝酰和超氧配合物的空腔强化结构和反应性

• 批准号: 2339280
• 负责人: Brandon Barnett
• 金额: $ 77万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-07-01 至 2029-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2339280&HistoricalAwards=false
• 关键词: CAREER; Cavity; Enforced; Structure; Reactivity

With support from the Chemical Synthesis program of the Division of Chemistry, Brandon R. Barnett of the University of Rochester is investigating the synthesis of biologically-inspired iron complexes that can facilitate the breaking of strong carbon-hydrogen bonds during chemical reactions. This process is essential for the chemical industry where many important processes require the breaking of such bonds in the usual chemical feedstocks. The proposed work aims to develop ways to perform such reactions and exert fine control over the carbon-hydrogen cleavage process. These studies will further develop strategies that enable the new iron compounds to be employed as catalysts and enable the efficient conversion of feedstocks to value-added products. Synergistically, the proposed work will develop essential technical and non-technical skill sets of early career trainees and facilitate the engagement of students from underrepresented backgrounds in modern chemistry research. Additionally, this project is well suited for outreach and training of students from across multiple educational levels and communities. Beyond the incorporation of undergraduate research into this project, the PI will initiate a summer workshop series, with the aim of developing the “soft skills” of undergraduate chemistry researchers. Complementing this effort is a plan to interface inner-city high school students with the proposed research, and to incorporate virtual reality technology into the graduate level curriculum.The proposed research will undertake mechanistic investigations of C-H activation by cavity-enclosed iron(IV)-oxos, which will be greatly aided by the ability to handle these complexes at ambient and moderately elevated temperatures. Importantly, the rigid nature of the cavity is anticipated to allow for steric selectivity in C-H activation, whereby regioselectivity is determined by the steric accessibility of the bond rather than its strength. Investigations into net C-H functionalization will be initiated, as will targeted approaches that can enable catalytic turnover. As an extension of scope, the proposed work will also elucidate the effects of spatial confinement on the electronic and geometric structures of iron superoxo and nitrosyl complexes. The targeted high-valent iron complexe will be built using a ligand system that contains an organic macrocycle atop a trigonal metal-chelating platform. These are designed to surround and kinetically stabilize the reactive metal-bound fragments. The proposed work aims to exploit an interplay between the ability of the cavity to enforce conformations of low thermodynamic stability, to suppress common degradation pathways, and to control substrate approach so as to achieve regioselective C-H functionalization, with potentially broad scientific impact and application, if successful.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.

在化学系化学合成项目的支持下，罗切斯特大学的 Brandon R. Barnett 正在研究生物启发的铁络合物的合成，该络合物可以促进化学反应过程中强碳氢键的断裂。对于化学工业来说至关重要，因为许多重要的过程都需要破坏常用化学原料中的此类键。拟议的工作旨在开发执行此类反应的方法并对碳氢裂解过程进行精细控制。这些研究将进一步制定策略。使新的铁化合物将用作催化剂，并使原料有效转化为增值产品。拟议的工作将开发早期职业培训人员的基本技术和非技术技能，并促进来自代表性不足背景的学生的参与。在现代化学研究领域，该项目非常适合对来自多个教育水平和社区的学生进行推广和培训，除了将本科生研究纳入该项目之外，PI还将启动一个夏季研讨会系列，旨在开发作为对本科化学研究人员“软技能”的补充，一项计划将城市内的高中生与拟议的研究结合起来，并将虚拟现实技术纳入研究生课程。拟议的研究将进行 C-H 激活的机制研究。通过空腔封闭的铁（IV）-oxos，这将大大有助于在环境温度和适度升高的温度下处理这些复合物的能力，重要的是，空腔的刚性性质预计将允许 C-H 活化中的空间选择性，因此，区域选择性取决于键的空间可及性，而不是其强度，将启动对净 C-H 官能化的研究，作为范围的扩展，拟议的工作也将阐明其影响。铁超氧和亚硝酰配合物的电子和几何结构的空间限制将使用包含三角顶部有机大环的配体系统构建。这些旨在包围和动力学稳定反应性金属结合片段，旨在利用空腔增强低热力学稳定性构象的能力之间的相互作用，以抑制常见的降解途径。控制底物方法，以实现区域选择性 C-H 功能化，如果成功，具有潜在广泛的科学影响和应用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。