Presentation Title
Iron (II) Pyridinediimine Complexes with Lewis Acids in the Secondary Coordination Sphere
Presentation Type
Poster
Abstract
In many biological and synthetic systems, electron-transfer reactions by redox-active transition metals often function by participating with redox-inactive metals to facilitate reactivity, such as the potassium-promoted iron surfaces used in the Haber-Bosch process, or the Ca2+ ion in the oxygen evolving complex of photosystem II. Inclusion of these redox-inactive Lewis acids have been shown to enhance electron-transfer rates and tune reduction potentials in synthetic chemical systems, as well as facilitate H-H, N-N and O-O bond cleavage.
In this work, we set out to design this feature into the redox non-innocent pyridinediimine (PDI) scaffold by synthesizing a family of Iron (II) pyridinediimine complexes with a 15-crown-5 ether moiety located in the secondary coordination sphere. This lead to a redox active metal-ligand complex with a Lewis acid in secondary sphere, as these pockets are perfectly sized to house metal ions such as Na+. We report here the synthesis and characterization of these complexes, including NMR analysis of the effect of binding Na+ in the pocket as well as electrochemical studies, which have demonstrated that these complexes exhibit modest shifts in the reduction potential of the metal-ligand scaffold upon encapsulation.
Start Date
6-5-2017 12:15 PM
End Date
6-5-2017 2:00 PM
Genre/Form
posters
Subjects - Topical (LCSH)
Iron; Oxidation reduction reaction; Lewis acids
Type
Event
Format
application/pdf
Language
English
Iron (II) Pyridinediimine Complexes with Lewis Acids in the Secondary Coordination Sphere
Miller Hall
In many biological and synthetic systems, electron-transfer reactions by redox-active transition metals often function by participating with redox-inactive metals to facilitate reactivity, such as the potassium-promoted iron surfaces used in the Haber-Bosch process, or the Ca2+ ion in the oxygen evolving complex of photosystem II. Inclusion of these redox-inactive Lewis acids have been shown to enhance electron-transfer rates and tune reduction potentials in synthetic chemical systems, as well as facilitate H-H, N-N and O-O bond cleavage.
In this work, we set out to design this feature into the redox non-innocent pyridinediimine (PDI) scaffold by synthesizing a family of Iron (II) pyridinediimine complexes with a 15-crown-5 ether moiety located in the secondary coordination sphere. This lead to a redox active metal-ligand complex with a Lewis acid in secondary sphere, as these pockets are perfectly sized to house metal ions such as Na+. We report here the synthesis and characterization of these complexes, including NMR analysis of the effect of binding Na+ in the pocket as well as electrochemical studies, which have demonstrated that these complexes exhibit modest shifts in the reduction potential of the metal-ligand scaffold upon encapsulation.