Q-Chem Webinar 56

Evaluating Oxidation States in Challenging Organometallic Complexes: What are the Electrons Doing?

Prof. Martin Head-Gordon
Presented by Prof. Martin Head-Gordon on

Martin Head-Gordon is the Kenneth S. Pitzer Distinguished Professor of Chemistry at the University of California at Berkeley and the Scientific Advisor to Q-Chem, Inc.  Dr. Head-Gordon's research group centers on the development of new electronic structure theory methods, and their implementation as efficient computer algorithms.  He is recognized with many awards, such as the Medal of the International Academy of Quantum Molecular Sciences (1998) and his election to the American Academy of Arts and Sciences (2011), the American Chemical Society Fellow (2012), and most recently, the Schrödinger Medal of WATOC (2020).



Oxidation states are of great interest in organometallic complexes, especially when non-innocent ligands are involved, together with multiple redox states. How are reducing equivalents stored? How are unusual oxidation states stabilized? Standard approaches for probing metal oxidation states such as examining spin populations are useful but have clear limitations. Q-Chem contains some powerful and nonstandard tools that provide insight into the presence or absence of redox non-innocence and provide an answer to the oxidation state question. In addition, these methods also yield the relevant orbitals behind key metal-ligand interactions. One existing method and one new approach will be reviewed in this talk. Their performance will be illustrated on a wide variety of examples, many of which present challenges for the IUPAC prescription for oxidation states.