Expanding Reduction Chemistry via the f Orbital Metals

University Of California-Irvine, Irvine CA

Investigators

Abstract

William Evans, University of California-Irvine, is supported by the Inorganic, Bioinorganic and Organometallic Chemistry Program for continuing studies of the special reduction chemistry of the f-element metals. These studies will concentrate on expanding reduction chemistry to complexes of traditionally non-redox active lanthanide metals, to combine traditional reduction methods based on redox active metals with ligand-based processes to generate multi-electron reductants, and to explore new options in reduction chemistry. The first part of this project is to develop systems where a divalent lanthanide is generated through reduction of a trivalent lanthanide precursor with an alkali metal. This process will be utilized with lanthanides that have no known molecular divalent states. Dinitrogen dianions formed by similar alkali metal induced reductions carried out in the presence of a trivalent lanthanide and dinitrogen will be developed for the reductive homologation of CO and related systems. A second part of the project involves the development of multi-electron reduction chemistry based on a combination of sterically induced reduction (a process where reduction is facilitated by extreme steric crowding in the reducing agent) and conventional metal-based redox. By combining these two effects, molecules will be developed to deliver a sequence of metal- and ligand-based reactions involving 2, 3, 4, 6, and 8 electrons per molecule. A third area of activity involves elaboration of the reaction chemistry of these reductive methods. Transformations of N2, CO, and CO2 will be studied and systems will be designed to make the chemistry catalytic. The unique properties of the lanthanide metals offer opportunities to develop new types of reductive reactivity. Since reduction is one of the basic types of chemical reactions, this can broadly impact both synthetic and catalytic chemistry. In addition, through this research, students will be trained in the chemistry of the f-elements.