Crystal structure of an unknown solvate of {2,2′-[ethane-1,2-diylbis(nitrilo­methanylyl­idene)]diphenolato-κ(4) O,N,N′,O′}(N-ferrocenylisonicotinamide-κN (1))cobalt(II): a Co(II)–salen complex that forms hydrogen-bonded dimers

The title compound, [CoFe(C(5)H(5))(C(16)H(14)N(2)O(2))(C(11)H(9)N(2)O)], was prepared as an air-stable red–brown solid by mixing equimolar amounts of {2,2′-[ethane-1,2-diylbis(nitrilo­methanylyl­idene)]diphenolato}cobalt(II) and N-ferrocenylisonicotinamide in dry di­chloro­methane under nitro­gen and was characterized by ESI–MS, IR, and single-crystal X-ray diffraction. The structure at 100 K has triclinic (P-1) symmetry and indicates that the complex crystallizes as a mixture of λ and δ conformers. It exhibits the expected square pyramidal geometry about Co, and forms hydrogen-bonded dimers through amide N—H groups and phenolate O atoms on an adjacent mol­ecule. The involvement of only half of the salen ring structure in hydrogen-bonding inter­actions results in slight folding of the salen ring away from the pyridine coordination site in the δ conformer with an inter-salicyl­idene fold angle of 9.9 (7)°. In contrast, the λ conformer is nearly planar. The dimers pack into an open structure containing channels filled with highly disordered solvent mol­ecules. These solvent molecules’ contributions to the intensity data were removed with the SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–18] available in PLATON.