New redox mediators and improved electrocatalytic materials for the functionalization of CH-bonds by electrosynthesis
01/10/2018 - 01/10/2022
Carbon-Hydrogen bonds are the most common bonds that occur in organic chemistry, they’re generally very strong, and unreactive. Because of the high dissociation energy associated with C-H bond activation ( the C-H bond dissociation in alkanes is 2.2-2.7 (V vs SHE)), molecules already containing functional groups will have them react at lower potentials, rendering late stage C-H functionalization useless. Chemical C-H activation is difficult to achieve, especially with C(sp3)-H bonds, it is expensive and associated with generation of a lot of waste.
Indirect C-H bond activation utilizes a Charge Transfer Mediator (CTM) (small nitrogen containing molecules in this case) which gets ionized at a lower potential then the C-H bond. The CTM then abstracts the Hydrogen from the Carbon, which leaves a highly reactive methylene radical which will attach itself to a reactive species in the neighborhood.
CTM’s are highly selective in which C-H bonds are activated, they can be reused and recycled, do not require toxic sacrificial oxidants, and electrons (driving force of the reaction) are pollution free.
The goal of this PhD is to improve the current electrochemical C-H activation by developing CTM’s and electrode materials that would be more efficient in electron transfer from the latter to the former.