Heteroleptic Triazole–Bisoxazoline Iron Complexes Reveal Lability of the Iron–Carbene Bond Even Within a Chelating Scaffold

N-Heterocyclic carbenes have proven to be excellent ligands for transition metals, with numerous applications in catalysis and beyond. However, they have also displayed lability with first row transition metals, largely due to the hard-soft mismatch of the metal-carbon bond. Chelation is often considered a suitable methodology for supporting the labile M-C bond through the introduction of a strongly coordinating donor site such as hard phenolates. Herein, we demonstrate that chelating phenolate-carbene ligands are kinetically labile in iron(II) complexes. Specifically, heteroleptic iron complexes [Fe(C^O)(N^N)] were synthesized composed of a phenolate-functionalized triazolylidene (CO) ligand and