Molecular Modeling of Redox Chemistry of Lignin-Carbohydrate Compounds
We are creating computer models of the molecules involved in our efforts at delignification of hemicelluloses. These models allow us to “see” reactive species that occur during the chemical reactions and could not otherwise be detected, and to evaluate the energy requirements of the various reaction pathways.
B3LYP/6-31+G* ab initio molecular orbital calculations are being performed on all species, including transition states, hypothesized to occur during the oxidation of aryl glycosides by hydroxyl radical and superoxide ion. These calculations suggest that the most feasible pathways for the observed cleavage reactions involve ipso attack on the aryl ring by an electrophilic aromatic substitution reaction. The reactions produce the sugar, which is further oxidized by hydroxyl radical, but not superoxide, and the phenol, which reacts further with both oxidizing species.
Other Partners On This Project
All work on this project is being performed by Ray Fort, with the support of the FBRI.
What’s New on this Project?
Our most recent results show that both hydroxyl radical and superoxide ion have energetically and mechanistically feasible pathways for breaking aryl glycosidic bonds.