High-Valent Non-Oxo-Metal Complexes of Late Transition Metals For sp3 C–H Bond Activation

With the support of the Chemical Synthesis program in the Division of Chemistry, Dr. Dong Wang of the University of Montana is studying new methodologies to generate transition metal complexes that are capable of converting inert hydrocarbons to their functionalized derivatives. This transformation is a key step in several processes involved in the production of fuels, chemicals, pharmaceuticals, clinical reagents, and agrochemicals, however, the underlying chemistry of this important transformation is still being developed.

In this project, Dr. Wang and his group plan to develop new complexes based on late first-row transition metals and a novel tridentate ligand platform discovered only recently. These metal complexes are expected to be strong oxidants to activate inert carbon-hydrogen bonds in hydrocarbon substrates and install desired functional groups on them.

Based on preliminary results, it is expected that this project will establish key relationships between the structures, spectroscopic properties and oxidative reactivities of these complexes, and will shed light on further developing this system to a catalytic hydrocarbon functionalization method. Further, this project will provide a solid training ground to educate Montana high school and Native American tribal college students and teachers in the field of bioinorganic chemistry by establishing a “Partnership in Bioinorganic Chemistry (PIBC)” program.

This program includes three interactive training and outreach components with scientific evaluation and assessment protocols, and is expected to advance science, technology, engineering, and mathematics (STEM) education within the local and Native American communities.

With the support of the Chemical Synthesis program in the Division of Chemistry, Dr. Dong Wang of the University of Montana is studying high-valent non-oxo-metal complexes of first-row late transition metals for the activation and functionalization of inert aliphatic carbon-hydrogen bonds. This transformation is a key step in many biological and synthetic processes, and studies that utilize earth-abundant first-row transition metal reagents are highly desirable.

In this project, Dr. Wang and his group propose to develop novel high-valent late transition metal complexes having unusual, formal +4 oxidation states and capable of activating strong saturated C–H bonds using a rigid, tridentate, dianionic N3 ligand platform. This research builds on their recently published work on generating and characterizing a bona fide Co(IV)-dinitrate complex that is both stable enough for characterization by X-ray crystallography and reactive enough to cleave strong C–H bonds.

In collaboration with the Jackson group at the University of Kansas, the Wang group aims to develop more reactive high-valent late transition metal complexes and systematically investigate their structure-reactivity relationship through computationally guided, rational modifications of the N3 ligand, coordinating anions, and the identity of the metal center. This research is expected to produce results that advance fundamental knowledge in high-valent chemistry for first-row late transition metal complexes, and shed light on future development of this system to a catalytic C–H bond functionalization method.

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.