Abstract:
The 2-pyridonate ligand framework has been explored in a variety of transition metal complexes. Interest in this ligand stems from its ability to adopt various binding modes, whether end-on, chelating, or bridging; its ease in being functionalized about the pyridyl ring to explore steric and electronic effects; or its proven track record in facilitating proton shuttling and redox activity.
[1] In the Schafer group, 2-pyridonates have been recently investigated on vanadium, resulting in complexes capable of catalyzing the reductive coupling of alcohols.
[2] Herein, I report the coordination chemistry of vanadium complexes with sterically varied 2-pyridonates, illustrating that the choice of 2-pyridonate ligand affects nuclearity of the complexes. Furthermore, I explore 2-aminopyridinates and 2-pyridinethiolates as more electron-rich1,3-N,N- and 1,3-N,S-chelating analogues of 2-pyridonate, respectively.
Density functional theory calculations are employed to gain insight into the metal-ligand bonding interactions that differ among the ligand classes. Finally, the complexes can be applied with varying efficacy as catalysts for the reductive coupling of alcohols or the deoxydehydration of vicinal diols.
(1) Fedulin, A.; Jacobi Von Wangelin, A. 2-Pyridonates: A Versatile Ligand Platform in 3d Transition Metal Coordination Chemistry and Catalysis. Catal. Sci. Technol. 2024, 14, 26-42.
(2) Griffin, S. E.; Schafer, L. L. Vanadium Pyridonate Catalysts: Isolation of Intermediates in the Reductive Coupling of Alcohols. Inorg. Chem. 2020, 59, 5256-5260.