Bimetallic Reactivity Enabled by Ligand Flexibility in (β-Dialdiminato)iron Complexes

Abstract

A group of iron complexes supported by a 2,6-diisopropylphenyl-substituted β-dialdiminate ligand have been prepared and characterized. The iron(II) chloride complex forms as the lithium chloride adduct that can be compared directly to its methyl-substituted β-diketiminate analog, revealing a more open iron center in the β-dialdiminate complex with a remarkable degree of rotation about the 2,6-diisopropylphenyl substituent. Exchange of chloride with phenylacetylide ligands generates a related fourcoordinate organometallic complex. Interestingly, the iron(I) phenylacetylene complex is unstable in solution, undergoing bimetallic coupling to generate an isomeric mixture of bimetallacyclic complexes. We propose that this process stems from increased flexibility in the β-dialdiminate ligand backbone and highlights the exciting opportunities that are presented by this system.