Syntheses, crystal structures and magnetic properties of [2 × 1 + 1 × 2] heterotetrametallic and [1 × 1 + 1 × 1] heterodimetallic cocrystals of copper(II) and iron(II/III)

► Cocrystals derived from N,N′-ethylenebis(3-ethoxysalicylaldimine) and N,N′-o-phenylenebis(3-ethoxysalicylaldimine). ► Two [2×1+1×2] CuIIFeII-2CuII cocrystals and one [1×1+1×1] FeIII-CuII cocrystal. ► Both structural and magnetic studies of only third and fourth examples of diphenoxo-bridged CuIIFeII cores. ► Weak or very weak antiferromagnetic interaction in the cocrystals. ► Water···O(phenoxo)2O(ethoxy)2 interaction responsible for the stabilization of the self-assemblies.