Main Group Catalysts for Activation Chemistries

美国国家科学基金会化学部的化学催化项目用这个奖项来支持麻省理工学院的Alexander Radosevich教授的研究，他正在研究一种基于轻质、廉价和丰富的非金属元素的新型催化剂。催化在大规模、经济和可持续的化学合成中起着核心作用，包括燃料、药物和材料。基于廉价和地球丰富元素的新型催化剂的开发支撑了新兴的反应化学，并推进了社会可持续发展的目标。在这个项目中，Radosevich博士和他的学生正在创造新的含磷化合物，这些化合物可以与简单的天然化合物如醇和氨发生反应。在这项研究中正在进行的具体反应包括从醇中去除氧和电化学氧化氨的方案，这两种反应都可能有助于化学物质的可再生生产和能量的转换。与Radosevich博士一起工作的研究生和本科生研究人员正在接受广泛的光谱、物理和合成化学技术方面的培训。实现这些培训目标有助于建立一支重要的劳动力队伍，支撑美国化学工业的经济竞争力。Radosevich博士和他的研究小组参与了许多推广工作，以推进广泛参与科学的目标。Radosevich博士的实验室还接待了许多具有不同经验水平的国际访问研究人员，为美国在国际科学参与中的持续领导地位做出了贡献。Radosevich致力于研究基于磷的新型氧化还原活性非金属催化剂的实验物理、热力学和机械基础。这项工作的中心命题是，在三坐标磷化合物上强制非三角几何将产生必要的结构和电子条件，以支持O-H和N-H活化引发的催化反应性。本实验建立了基于主基团的非三角三坐标磷的醇脱氧和氨氧化新方法。研究的具体领域包括描述取代基对非三角三配位磷化合物的最高占据分子轨道(HOMO)-最低未占据分子轨道（LUMO）电子结构的作用和程度，以及通过对开壳四配位磷酰的键裂解建立五配位烷氧磷烷的实验键焓趋势。本研究还发展了非三角三配位磷催化剂的基本反应化学，支持根据N-H活化形成新的N-N键反应。总之，这些研究提供了一个详细的，实验量化的非三角畸变对三坐标磷的电子结构的影响，使p-阻滞氧化还原催化一系列小分子转化反应成为可能。除了科学目标外，该项目还支持本科生和研究生的技术培训和发展，促进维持一支训练有素的国内化学劳动力队伍。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 this award, the Chemical Catalysis Program of the NSF Division of Chemistry is supporting the research of Professor Alexander Radosevich of the Massachusetts Institute of Technology who is studying a new class of catalysts based on lightweight, inexpensive, and abundant nonmetal elements. Catalysis plays a central role in the scalable, economical, and sustainable synthesis of chemicals, including fuels, drugs, and materials. The development of new catalysts based on inexpensive and earth-abundant elements underpins emerging reaction chemistries and advances society's goals for sustainability. In this project, Dr. Radosevich and his students are creating new phosphorus-containing compounds that react with simple and naturally occurring compounds such as alcohols and ammonia. The specific reactions being pursued in this research include schemes to remove oxygen from alcohols and electrochemically oxidize ammonia, both of which may contribute to the renewable production of chemicals and the conversion of energy, respectively. Graduate and undergraduate researchers working with Dr. Radosevich are receiving training in a broad set of spectroscopic, physical, and synthetic chemistry techniques. Achieving these training objectives contributes to a vital workforce that underpins the economic competitiveness of US chemistry-based industries. Dr. Radosevich and his research group participate in a number of outreach efforts advancing the goal of broad participation in science. Dr. Radosevich's laboratory is also host to numerous visiting international researchers at all levels of experience, contributing to ongoing US leadership in international scientific engagement.Dr. Radosevich is pursuing the experimental physical, thermodynamic, and mechanistic foundations for the development of a broad new class of redox active nonmetal catalysts based on phosphorus. This work centers on the proposition that enforcing nontrigonal geometries on tricoordinate phosphorus compounds will yield the structural and electronic conditions necessary to support catalytic reactivity initiated by O-H and N-H activation. The experiments establish new main group-based approaches to alcohol deoxygenation and ammonia oxidation at nontrigonal tricoordinate phosphorus. Specific areas being addressed include delineating the role and magnitude of substituent effects on the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) electronic structure of nontrigonal tricoordinate phosphorus compounds and establishing trends in experimental bond enthalpies for pentacoordinate alkoxyphosphoranes through bond cleavage to open-shell tetracoordinate phosphoniumyls. The research also develops elementary reaction chemistry at nontrigonal tricoordinate phosphorus catalysts supporting a new N-N bond forming reaction pursuant to N-H activation. Together, these studies are providing a detailed, experimental quantification of the impact of nontrigonal distortion on electronic structure in tricoordinate phosphorus that are enabling p-block redox catalysis for a range of small molecule conversion reactions. Apart from the scientific objectives, this project supports the technical training and development of undergraduate and graduate students, facilitating the maintenance of a well-trained domestic chemical workforce.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.