Diimine–Dioxime Acenaphthene Cobalt Complexes: Characterization of the Novel <i>cis</i> Coordination Mode

Abstract During the synthesis of a new family of diimine–dioxime acenaphthene cobalt complexes a novel cis coordination mode was observed for (DA Bn )Co(Py)Br ( 4 ), along with the expected trans coordination mode for [(DA En )Co(L) 2 ]BPh 4 ( 2 ). The new coordination mode for this class of compounds is fully characterized. We explore the influence of linker length, ligand protonation, and supporting ligands on the preference for the cis vs. trans coordination mode using experimental and computational methods. Increased flexibility, increased acidity, and large supporting ligands all support the preference for the cis coordination mode.