Professor Michael Rose

Professor Michael Rose
Department of Chemistry
University of Texas at Austin

Reactivity Outcomes from Dynamics and Symmetry: From Metalloenzyme Models ([Fe]-Hydrogenase) to Semiconductor Photoelectrochemistry (Silicon)

Understanding how electronic structure and molecular mo- tion govern chemical reactivity remains a central challenge in inorganic chemistry, spanning discrete coordination com- plexes and extended solid-state systems. The Rose Research Group integrates synthetic inorganic chemistry, spectroscopy and theory to elucidate the effects of structure, symmetry and dynamics in inorganic systems. 

The first part of the talk focuses on bioinorganic modeling of mono-[Fe] hydrogenase, which catalyzes H2 activation and hydride transfer in the methanogenic reduction of CO2 to methane. We have developed a family of synthetic iron complexes that systematically vary the donor atom environment to provide mechanistic insight into H2 activation and hydride transfer. We use a distal and rigid ‘anthracene scaffold’ design that reproduces the enzyme active site. We have extended our ‘distal scaffold’ approach to investigate the role of molecular dynamics in reaction dynamics. Substitution of more dynamic, tricyclic scaffold units (e.g. thianthrene) provides more ‘protein- like’ dynamic environment, showing how activation dynamics and activation entropy can be leveraged to provide enhanced kinetics in model systems. 

Secondly, we examine semiconductor photoelectrochemistry from a pure inorganic perspective, treating semiconductors as extended solids with well-defined symmetry and electronic structure rather than black-box materials: band structures are often discussed without symmetry-based language familiar to inorganic chemists. We introduce a framework that translates semiconductor band structure into an orbital and group-theory description, enabling rational design of molecular interfaces that hybridize with specific electronic states of the solid. Using silicon as a model system, we investigate how surface orientation, band symmetry and molecular orbital symmetry modulate interfacial electron transfer.

Michael Rose

After growing up in Los Angeles, Mike graduated with a B.S. from UC Davis, then worked in industry for two years at Roche Pharamaceuticals in Palo Alto, CA working on kinetic mechanisms of biochemical inhibitor action. Mike then earned his PhD in Chemistry at UC Santa Cruz for biochemistry, working with Prof Pradip Mascharak (a Dick Holm / Steve Lippard protégé), pursuing iron-sulfur chemistry in the form of synthetic models of Fe-Nitrile- Hydratase — as well as synthesis of Ruthenium- nitrosyls for photodynamic therapy. Mike then did postdoctoral research at Caltech, co-advised by Profs Harry Gray and Nate Lewis as part of a NSF CCI Solar research center. His research focused on fluorinated iron-based H2 electrocatalysts, and the covalent attachment of molecular catalysts to silicon for photo-electrochemical H2 generation. As an Assistant Professor, he developed synthetic mimics of the hydride-transfer enzyme [Fe]-Hydrogenase, as well as constructing hybrid molecular|materials interfaces for photo-electrochemical energy conversion. In his current research phase, he has used dynamic synthetic scaffolds to understand the link between ‘protein-inspired’ dynamics and reactivity in [Fe]-hydrogenase model compounds. In the area of photo-electrochemistry, he has devised a means to understand and predict interfacial hybridization between molecular orbitals and semiconductor band structure, with the aim of enhancing light-to- chemical energy conversion processes. He has held the Ferne & Evan Kybra Professorship in Chemistry, and is now the Director of the Bard Center for Electrochemistry at UT Austin. In his spare time, Mike enjoys spending time with his family, playing soccer, trail running and racing around Austin, listening to 90s rock, and challenging other research groups to kickball matches.

Hosted by Professor Gwendolyn Bailey