High-Valent Non-Oxo-Metal Complexes of Late Transition Metals For sp3 C–H Bond Activation

在化学系化学合成项目的支持下，蒙大拿大学的王东博士正在研究生成过渡金属配合物的新方法，这些过渡金属配合物能够将惰性碳氢化合物转化为其功能化衍生物。这一转变是生产燃料、化学品、药品、临床试剂和农用化学品的几个过程中的关键步骤，然而，这一重要转变的基础化学仍在开发中。在这个项目中，王博士和他的团队计划开发基于第一排过渡金属的新配合物和最近才发现的新型三叉配体平台。这些金属配合物有望成为强氧化剂，激活碳氢化合物底物中的惰性碳氢键，并在其上安装所需的官能团。在初步研究的基础上，本项目有望建立这些配合物的结构、光谱性质和氧化反应性之间的关键关系，并为进一步将该体系发展为催化烃类功能化方法提供思路。此外，该项目将通过建立“生物无机化学伙伴关系（PIBC）”项目，为蒙大拿州高中和美国土著部落大学的学生和教师提供生物无机化学领域的坚实培训基础。该项目包括三个互动培训和推广部分，包括科学评估和评估协议，预计将在当地和美洲原住民社区推进科学、技术、工程和数学（STEM）教育。在化学系化学合成项目的支持下，蒙大拿大学的王东博士正在研究第一排晚期过渡金属的高价非氧金属配合物，用于惰性脂肪族碳氢键的活化和功能化。这种转化是许多生物和合成过程的关键步骤，利用地球上丰富的第一行过渡金属试剂进行研究是非常可取的。在这个项目中，王博士和他的团队建议开发新的高价晚期过渡金属配合物，具有不寻常的，正式的+4氧化态，能够使用刚性的，三叉的，重阴离子的N3配体平台激活强饱和的C-H键。这项研究建立在他们最近发表的关于生成和表征真正的Co(IV)-硝酸络合物的工作基础上，该络合物既足够稳定，可以用x射线晶体学进行表征，又足够活跃，可以切割强碳氢键。Wang小组与堪萨斯大学的Jackson小组合作，旨在开发更具活性的高价晚期过渡金属配合物，并通过计算指导，合理修饰N3配体，配位阴离子和金属中心的身份，系统地研究它们的结构-反应性关系。本研究的结果有望推动第一行晚期过渡金属配合物的高价化学基础知识，并为该体系的未来发展指明方向，以催化C-H键功能化方法。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。

With the support of the Chemical Synthesis program in the Division of Chemistry, Dr. Dong Wang of the University of Montana is studying new methodologies to generate transition metal complexes that are capable of converting inert hydrocarbons to their functionalized derivatives. This transformation is a key step in several processes involved in the production of fuels, chemicals, pharmaceuticals, clinical reagents, and agrochemicals, however, the underlying chemistry of this important transformation is still being developed. In this project, Dr. Wang and his group plan to develop new complexes based on late first-row transition metals and a novel tridentate ligand platform discovered only recently. These metal complexes are expected to be strong oxidants to activate inert carbon-hydrogen bonds in hydrocarbon substrates and install desired functional groups on them. Based on preliminary results, it is expected that this project will establish key relationships between the structures, spectroscopic properties and oxidative reactivities of these complexes, and will shed light on further developing this system to a catalytic hydrocarbon functionalization method. Further, this project will provide a solid training ground to educate Montana high school and Native American tribal college students and teachers in the field of bioinorganic chemistry by establishing a “Partnership in Bioinorganic Chemistry (PIBC)” program. This program includes three interactive training and outreach components with scientific evaluation and assessment protocols, and is expected to advance science, technology, engineering, and mathematics (STEM) education within the local and Native American communities.With the support of the Chemical Synthesis program in the Division of Chemistry, Dr. Dong Wang of the University of Montana is studying high-valent non-oxo-metal complexes of first-row late transition metals for the activation and functionalization of inert aliphatic carbon-hydrogen bonds. This transformation is a key step in many biological and synthetic processes, and studies that utilize earth-abundant first-row transition metal reagents are highly desirable. In this project, Dr. Wang and his group propose to develop novel high-valent late transition metal complexes having unusual, formal +4 oxidation states and capable of activating strong saturated C–H bonds using a rigid, tridentate, dianionic N3 ligand platform. This research builds on their recently published work on generating and characterizing a bona fide Co(IV)-dinitrate complex that is both stable enough for characterization by X-ray crystallography and reactive enough to cleave strong C–H bonds. In collaboration with the Jackson group at the University of Kansas, the Wang group aims to develop more reactive high-valent late transition metal complexes and systematically investigate their structure-reactivity relationship through computationally guided, rational modifications of the N3 ligand, coordinating anions, and the identity of the metal center. This research is expected to produce results that advance fundamental knowledge in high-valent chemistry for first-row late transition metal complexes, and shed light on future development of this system to a catalytic C–H bond functionalization method.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.