Pyridinediimine Complexes with Coordination Sphere Interactions Relevant to Copper and Non-Heme Iron Enzymes
Year: 2021
Type: article
Abstract: Primary and secondary coordination sphere interactions with proximal Brønsted-Lowry acid/base sites were investigated using a family of pyridinediimine (PDI) complexes. The PDI ligands used in this project could be easily prepared by the Schiff base reactions with commercially available diamines as proton relays. Upon activation, the pendant Bronsted site and accessible electrons were arranged in a single scaffold that allowed the transportation of both protons and electrons to occur. Two new PDI complexes with morpholine and pyrrolidine derivatives were introduced to the pendant PDI family. Their proton dissociation constant in acetonitrile were 17.1 and 18.3, respectively. The PDI complexes were subjected to reactions with nitrite and monitored via UV-Vis and IR spectroscopy, in which they exhibited much faster initial rates than some of the previously reported pendant PDI complexes. The rate enhancement effect was clearly evidenced by the stability of the corresponding mononitrosyl iron complex (MNIC) intermediate. These results had not yet been observed in other mononuclear PDI complexes and was attributed to the unique combination of proton responsivity, redox-activity and hemilability in the new pendant PDI systems.
Author: Pui Man Cheung
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3180526718