Iron carbene complexes have been identified as important intermediates in many catalytic transformations such as carbene insertion into E-H bonds and cyclopropanation of olefins. While several examples of isolable and well-characterized iron carbene species have been reported, their exact electronic structures remain an issue of ongoing debate. This is particularly the case for paramagnetic derivatives, which form a rare subset of iron carbene compounds. This presentation will focus on the first iron carbene complex with a square-planar coordination environment recently discovered by our research group. This unusual structural motif produces an orbitally near-degenerate electronic ground state resulting in highly anisotropic magnetic properties and very large zero-field splitting due to unquenched orbital angular momentum. Despite the unique electronic structure compared to other iron carbene complexes, carbene transfer to organic substrates proceeds readily involving reversible carbene insertion into an Fe-N bond of the supporting ligand framework.

Paramagnetic, square-planar iron carbenes: Insights into electronic structure and reactivity

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.