Co-crystallization of isomers of iron(II) complex of a tridentate mixed amine/imine ligand in one unit cell

The X-ray study of an octahedral iron(ii) complex with a tridentate mixed amine/imine Schiff base ligand L derived from pyridine-2-carboxaldehyde and 1,2-diaminocyclo- hexane revealed that its single crystals consisted of a mixture of stereoisomers co-crystallized in one unit cell. Thus, Werner-type complexes formulated as [Fe(trans-(1R,2R)-L)₂](PF₆)₂, [Fe(trans-(1S,2S)-L)₂](PF₆)₂, and [Fe(trans-(1R,2R)-L)(trans-(1S,2S)-L)](PF₆)₂ were identified within the structure. Observation of a good quality ¹H and ¹³C{¹H} NMR spectra evidenced the low-spin configuration of the central atom.