Non-Innocent Main Group Centers for Targeted Multi-Electron Transformations

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

Catalysts are species that improve the speed, the energy consumption, and/or the efficiency of chemical reactions; they are essential for industrial chemistry and for biological processes. The design of new catalysts is an important area of research as there is continual need for them in order to develop more efficient chemical processes. A special class of catalysts are those that can facilitate a flow of electrons to perform multi-electron chemical transformations. Professor Gabriel Menard, Chemistry Department, University of California - Santa Barbara, is supported by the Chemical Synthesis Program of the Chemistry Division to develop new catalysts for multi-electronic processes. These catalysts are based on inexpensive, abundant metals that are able to transfer electrons to and activate a non-metal center. This is nearly opposite the usual design in which the electron transfer goes from a non-metal to activate a metal center. These new catalysts open new processes to everyday goods and utilize common, inexpensive starting materials. Students from underrepresented groups are engaged in this research and Professor Menard seeks to increase broader scientific literacy by hosting a free, monthly "Science Pub Night" event, where scientists present their research to the public in an open and accessible way. This project investigates how tethering multi-metallic redox-active platforms to group 13 or group 15 centers facilitate multi-electron transformations at the main-group site. A goal is to develop main-group catalysts for multi-electron processes. By coordinating vanadium to various ligands, complexes with a variety of redox properties are obtained. These are attached to group 13 or 15 centers to generate species that contain up to three vanadium moieties attached to a main-group atom. The compounds are characterized by the usual chemical and spectroscopic techniques, with particular attention being paid to the electrochemical and magnetic properties. The presence of several vanadium atoms provides the ability for cooperative, multi-electron redox chemistry at the main group unit. This reactivity is probed in atom or group transfer chemistry and for the activation of water, ammonia, and hydrogen. This research provides excellent training to undergraduate and graduate students in the synthesis and characterization of typically air sensitive molecules. This prepares them for careers in academia, industry, or national laboratories. 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.