From Fundamental Investigations to Catalysis: New Motifs in Main Group and Transition Metal Complexes

点击翻译按钮获取中文摘要

The last 3 years have seen an extensive redefinition of our research program, goals and training environment. These directions center on photocatalytic and electrocatalytic approaches to energy and environmentally relevant targets. This proposal addresses fundamental aspects of chemical design in concert with catalyst development and makes for a unique program and excellent training environment. Specifically, the proposal presents three fully integrated research themes. The first builds on our pioneering, fundamental objective to design and assemble molecular scaffolds with unconventional metal-ligand bonding interactions, unusual metal coordination geometries, and tailored electronic anisotropy of the coordinated metal. The impact of these important fundamental interactions has recently been appreciated in the literature to which we contributors. Our strategy exploits ligands with restricted geometric features that dictate the alignment of their bonding orbitals. The resulting changes to physical and chemical properties of the complexes will support the other two themes and lead to unprecedented reactivity and catalysis. These plans employ several families of ligands that will be applied for discovery in the catalysis streams. ***The second research stream focuses on electrocatalytic routes for reduction of CO2 to yield C1 products and the generation of H2 from neutral water. The transformation of CO2 provides the potential to recycle this ubiquitous combustion by-product into energy containing products. Success here will result in a paradigm shift to viewing CO2 as a feedstock rather than as a waste product. Electrocatalytic routes to H2 from water provide a clean and renewable fuel with enormous potential to address the world's energy demands while simultaneously fulfilling a mandate for environmental stewardship. The proposal presents several lines of research that use the complexes designed in the first research theme. Our focus is on earth-abundant metal complexes and involves variation of the metal center as well as targeted sites of ligand modification. ***Light can provide an alternative energy source for catalysis and homogeneous photocatalytic routes to H2 generation and transformation/reduction of CO2 are core to the third theme of our program. Again, the focus is on earth-abundant metal complexes that will be derived from the first research stream. Plans will include targeting specific sites of modification, which will modulate the electron donation to the catalytic metal center and the pi-conjugation of scaffold.***The results from our two catalysis-based themes will be used to dictate complex design and synthesis leading to a positive feedback loop that will not only improve activity but will also lead to discovery of entirely new catalysts. Overall, our approach plans to remove some of the serendipitous features of this field. *****