CAS: Collaborative Research: Electronic Structure/Function Relationships in Base Metal Complexes Spanning the Oxo/Oxene and Imide/Nitrene Continuum

在化学系化学结构、动力学和机制B计划的支持下，哈佛大学的Theodore A.Betley教授和康奈尔大学的Kyle M.Lancaster教授通过将廉价的小分子转化为更高附加值、更复杂的分子(如药物)来合成分子和材料。为了完成这些转变，该小组使用基于金属的催化剂来加速反应，并选择性地生产所需的产品，而不是不那么可取的副产品。从他们的催化反应中获得的知识可能有助于在美国实现可持续的化学工业。研究小组特别专注于设计和开发催化剂，用丰富、廉价和无毒的金属取代当今使用的贵金属催化剂，在某些情况下，还包括有毒的金属基催化剂。贝特利教授和兰卡斯特教授参与了教育推广活动，以吸引大学预科、本科生(大学内部和外部)和研究生层面的学生。研究人员组织并参与了来自当地小学和高中的K-12级学生的互动演示。在这个由化学系化学结构、动力学和机制B计划资助的项目中，哈佛大学的西奥多·A·贝特利教授和康奈尔大学的凯尔·M·兰卡斯特教授研究了C-H键功能化的电子结构设计。这位合成无机化学家和无机光谱学家的合作试图为主基配体上的自由基积累与贱金属C-−氢键功能化催化的相关性提供新的视角。这些信息对于促进基本理解和综合方法论都至关重要。这项研究涉及到新型金属-配体多键(MLMB)系统的合成和表征，该系统模仿生物单加氧酶，将不同的功能传递到C-H键底物。选择性地将官能团结合到未活化的C-H键中的能力代表着在将廉价的化学原料(例如碳氢化合物)转化为增值分子(例如药物前体)方面的进步。为此，Betley和Lancaster试图合成具有N-和O-功能的MLMB络合物，以检查和利用它们的反应化学反应。Betley和Lancaster建议利用N和O的K-边XAS作为手段来探索配位的N和O基配体给体的亚八位组特征，并量化配位络合物中的金属-配体共价性。这些数据将被用来使MLMB络合物在第一过渡系列后期的反应性(亲核性与亲电性)的周期性趋势合理化。本科生、研究生和博士后学者来自科学领域中代表性不足的群体，对于实现可持续发展目标是不可或缺的。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。

Supported by the Chemical Structure, Dynamics, and Mechanisms B program of the Chemistry Division, Professors Theodore A. Betley of Harvard University and Kyle M. Lancaster of Cornell University synthesize molecules and materials by converting inexpensive, small molecules into higher value-added, more complex molecules such as pharmaceuticals. To accomplish these transformations, the group uses metal-based catalysts to speed up reactions and to selectively produce desired products over less desirable byproducts. The knowledge gained from their catalysis reactions may contribute to achieving a sustainable chemical industry in the United States. The research team is particularly focused on designing and developing catalysts that substitute abundant, inexpensive and non-toxic metals for the precious and, in some cases, toxic metal-based catalysts used today. Professors Betley and Lancaster are involved in educational outreach activities to engage students at the pre-university, undergraduate (internal and external to the university), and graduate levels. The researchers organize and participate in interactive demonstrations for students at the K-12 level from local grade schools and high schools. In this project ,funded by the Chemical Structure, Dynamics, and Mechanisms B program of the Chemistry Division, Professors Theodore A. Betley of Harvard University and Kyle M. Lancaster of Cornell University examine electronic structure design for C-H bond functionalization. This collaboration between a synthetic inorganic chemist and inorganic spectroscopist seeks to provide new perspectives on the correlation of radical accumulation on main-group ligands towards base-metal C−H bond functionalization catalysis. Such information is critical to advancing both fundamental understanding as well as synthetic methodologies. The research involves the synthesis and characterization of novel metal-ligand multiple bonded (MLMB) systems that mimic biological monooxygenases that deliver diverse functionalities into C-H bond substrates. The ability to selectively incorporate functionality into unactivated C-H bonds represents an advance in converting inexpensive chemical feedstocks (e.g. hydrocarbons) to value-added molecules (e.g., pharmaceutical precursors). To this end, Betley and Lancaster seek to synthesize MLMB complexes featuring N- and O-bearing functionalities to examine and harness their reaction chemistry. Betley and Lancaster propose to leverage N and O K-edge XAS as means to probe the sub-octet character of coordinated N- and O-based ligand donors and to quantify metal-ligand covalency in coordination complexes. These data will be used to rationalize periodic trends in the reactivity (nucleophilic vs. electrophilic) of MLMB complexes across the late first transition series. Undergraduates, graduate students, and postdoctoral scholars from groups that are underrepresented in science are integral to carrying out the sustainability aims.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.