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Professor Nilay Hazari, Yale University
Tuesday, November 15, 2022, 11:00am - 12:00pm
 

Nilay HazariFundamental Studies of Hydride Transfer Related to Hydrogenative Processes

Hydride transfer, either from a transition metal hydride to an organic substrate or from an organic substrate to a transition metal to form a transition metal hydride, is the turnover-limiting step in many important transition metal catalyzed reactions. For example, in CO2 hydrogenation to formate or methanol a transition metal hydride donates a hydride to CO2, whereas in the reverse dehydrogenation of formic acid or methanol, these substrates donate a hydride to the metal catalyst.  Therefore, an increased understanding of hydride transfer with transition metals as either the hydride donor or acceptor is critical for the design of efficient catalysts for current and new reactions. In this talk, we describe fundamental kinetic and theoretical studies, which explore the factors that are important in the donation of a transition metal hydride to CO2. Specifically, we explore solvent and Lewis acid effects and show that the magnitude of these effects depends on the mechanism of hydride transfer to CO2. Additionally, by comparing the rates of hydride transfer from a transition metal hydride to a wide variety of substrates we develop linear-free energy relationships between thermodynamic and kinetic hydricity. We show that these relationships fail with even small changes in the steric environment around either the metal hydride or organic hydride acceptor. Finally, we present guidelines for designing improved catalysts based on our fundamental studies.

 

Hosted by Professor Kate Waldie

Location CCB Auditorium, Room 1303