Structurally diverse pyridyl or quinolyl enolato/enamido metal complexes of Li, Zr, Fe, Co, Ni, Cu and Zn

• Modular synthesis of pyridyl and quinolyl enolato and enamido ligands.
• Simple κ2 and unusual η5 coordination modes.
• Monomeric to trimeric cage assemblies.
• Oxido-bridged bimetallic and oxido-centered trimetallic clusters.

Simple β-ketiminates and β-diketiminates are important monoanionic [N,O] and [N,N] chelating ligand systems with a rich coordination chemistry across the periodic table of elements. New structurally related ligands having one imine donor annelated by an heteroaromatic ring system were easily accessible by reacting α-picolyl/quinolyl-lithium with nitriles followed by sequential acidic hydrolysis and condensation with primary aromatic amines. The coordination chemistry of these [N,O] and [N,N] ligands was fully explored with metals ranging from group 1 to group 12 (M = Li–Zn) resulting in a large variety of coordination modes, including common k2 and rare h5 motifs as well as novel oxido and non-oxido-bridged cluster assemblies, as shown by a total of 19 single crystal structure analyses.

Pyridyl/quinolyl-annelated enolates or enamides are easily accessible by a modular synthesis starting from α-picoline or quinoline. Their coordination chemistry is surprisingly rich, as evidenced by X-ray single structure analyses of simple [N,O]/[N,N]nM monomeric complexes, higher nuclearity assemblies with or without incorporated oxido ligands, and unusual π-complexes.Figure optionsDownload as PowerPoint slide