On the Solvent‐free Structure of a Jäger‐type Cobalt(II) N2O2‐Chelate Complex

A combined synchrotron X-ray and density functional theory (DFT) study on the structure of a Jager-type N2O2 chelate complex was carried out. The ethoxy-substituted bis(3-oxo-enaminato)cobalt(II) complex (1) was an original sample from the laboratory of the late Professor Ernst-G. Jager (University of Jena, Germany). Single-crystal X-ray analysis revealed essentially flat molecules of 1, which are unsolvated and coordinatively unsaturated. The DFT calculations on the isolated molecule predict a planar structure for the non-hydrogen atoms, which is a local minimum on the energy surface. The crystal packing is achieved through off-set stacking (staircase arrangement), resulting in a herringbone pattern in the space group P212121. The structure of 1 is compared to known structures of related bis(3-oxo-enaminato)cobalt(II) complexes (2–4). Original bulk material of 1 was investigated by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), melting point determination, and infrared (IR) spectroscopy.