Marcetta Darensbourg (Texas A&M)

Location: 127 Nieuwland Science Hall

Abstract: The merger of classical organometallic structure and bonding principles with biological ligands offers an almost unlimited chemical design space for new compounds, including potential catalysts, particularly targeting model mechanisms of the active sites in redox-processing enzymes. Our pursuit of bimetallic complexes has been inspired by two strategies found in Nature for “tricking” abundant first row transition metals into providing accessibility to 2-electron processes: redox-active ligands (such as pendant iron-sulfur clusters) and proximal metals, typically bridged by sulfur. Such arrangements permit base metals to compete with noble metals such as Palladium and Platinum, the kings of catalysis. Active sites of the diiron and nickel-iron hydrogenases (for hydrogen production or activation) and Acetyl coA Synthase (ACS, for C-C coupling reactivity) are well known prototypes that continue to stimulate inorganic synthesis. Our design has applied both strategies placing well known “noninnocent” ligands such as Nitric Oxide and dithiolenes on Fe and Ni, generating S-bridged bimetallic complexes with intricate physical properties, including closely spaced spin states applicable to molecular magnetism. (doi.org/10.1073/pnas)

Originally published at chemistry.nd.edu.