New Vistas in Porphyrinoid Chemistry: Corrolazine Synthesis and Reactivity

Johns Hopkins University, Baltimore MD

Investigators

Abstract

This research award in the Inorganic, Bioinorganic and Organometallic Chemistry Program supports work by Professor David Goldberg at Johns Hopkins University to carry out fundamental studies on the synthesis and reactivity of a new class of transition metal porphyrin-like compounds known as corrolazines. Methodology is being developed to synthesize new metallocorrolazines, focusing on manganese and iron complexes. The corrolazine ligand is designed to stabilize high oxidation states, and the synthesis and characterization of high-valent metal-oxo species are targeted. The metals iron and manganese have been selected for study because of their widespread use in synthetic catalysts as well as in biologically-relevant environments such as heme proteins. The reactivity of these species in oxygen-atom-transfer and hydrogen-atom-transfer reactions is under investigation. The influence of the corrolazine ligand on the stability and reactivity of these high-valent metal species is being examined, as well as the role of ancillary ligands. High-valent metal-oxo complexes and related high oxidation state species play key roles in a number of catalytic processes and biological systems, including heme enzymes, but they are difficult to study because of their inherent instability. The corrolazine platform is designed to increase their stability and allow for their direct examination, providing fundamental insights into their spectroscopic properties, reactivity, and mechanism of action. Through participation in this fundamental research, students at the undergraduate, graduate, and postdoctoral levels are receiving intensive training in state-of-the-art inorganic and bioinorganic chemical methods. They are gaining the skills necessary to become independent scientists, such as formulating and testing hypotheses and analyzing and interpreting experimental data in a conceptual framework. The knowledge gained from this research should help in the design of novel synthetic catalysts for industrial processes, and the research should also provide fundamental insights into biologically-relevant metalloenzymes.