Configuring first-row metal-metal bonded complexes to boost redox flexibility and N2 reduction activity

氮对生命至关重要，有许多重要用途，包括肥料、塑料成分和药物成分。事实上，氮含量丰富且易于获取，因为它占地球大气的78%。然而，大气中的氮气很难转化为可用于实际应用的形式。事实上，将大气中的氮转化为氨（农业肥料和许多工业过程的基本成分）的工业利用了大量的能量，而将大气中的氮直接转化为许多其他工业化学品的技术还没有发展起来。在这个由化学部化学合成项目资助的项目中，双城明尼苏达大学的Connie Lu教授正在通过开发将大气中的氮转化为氨以外的化学物质的方法来解决这些问题。该方法利用钴和铁化合物将电子转移到氮上。这激活了氮，并使其转化为一类被称为胺的化合物，这是许多重要工业化学品的基本组成部分。该项目包含强大的教育组成部分，其中本科生和研究生为未来的科学和技术职业进行培训。此外，一个扩展组件为中学生和高中生提供实验模块，教授可持续性和催化的主题。第一排金属-金属键配合物的氧化还原过程比单个金属的氧化还原过程更灵活。这种效应在多金属化合物中可见，多金属化合物是广泛的有机和无机转化的多功能催化剂。利用这一性质制备二氮转化为胺的催化剂。制备了一系列双金属Co-M和Fe-M （M = Al, Ti， V, Cr, Co）配合物，并用同步加速器和理论方法对其氧化还原柔韧性进行了表征。研究了这些物种催化二氮硅化反应的能力，并通过化学和理论研究确定了这一过程的机理。目标是设计催化N&amp；#8722；C键直接由二氮形成。通过这些活动，本科生和研究生在合成、催化剂开发和机械研究方面变得熟练。另一个外联部分是通过以实验为基础的催化讲习班，针对初高中女生。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。

Nitrogen is essential to life and has many important uses including fertilizers, components of plastics, and ingredients of pharmaceuticals. Actually, nitrogen is abundant and easily accessible as it makes up 78% of the Earth's atmosphere. However, atmospheric nitrogen gas is very difficult to convert into forms that can be used for practical applications. In fact, the industrial conversion of atmospheric nitrogen into ammonia (the basic component of agricultural fertilizer and many industrial processes) utilizes extreme amounts of energy and the conversion of atmospheric nitrogen directly to a number of other industrial chemicals is not developed. In this project funded by the Chemical Synthesis program of the Chemistry Division, Professor Connie Lu of the University of Minnesota, Twin Cities is addressing these problems by developing ways to convert atmospheric nitrogen into chemicals other than ammonia. The methods utilize cobalt and iron compounds to transfer electrons to nitrogen. This activates the nitrogen and permits it be converted to a class of compounds know as amines, which are the basic building blocks for many industrially important chemicals. The project contains a strong educational component in which undergraduate and graduate students are trained for future careers in science and technology. Additionally, an outreach component provides experimental modules for middle and high-school students to teach topics of sustainability and catalysis.The redox processes available to first-row metal-metal bonded complexes can be more flexible than those of individual metals. This effect is seen in multi-metallic compounds, which are versatile catalysts for a broad range of organic and inorganic transformation. This property is utilized to prepare catalysts for the conversion of dinitrogen to amines. A series of bimetallic Co-M and Fe-M (M = Al, Ti, V, Cr, and Co) complexes are prepared and their redox flexibility characterized by synchrotron and theoretical methods. The ability of these species to catalyze the silylation of dinitrogen is investigated and the mechanism of this process is determined by chemical and theoretical studies. The goal is to devise catalytic N−C bond formation directly from dinitrogen. Throught these activities undergraduate and graduate students become skilled in syntheis, catalyst development, and mechanistic studies. A further outreach component targets middle and high school girls through experimentally based catalysis workshops.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.