Crystal structure determination of an FeII azo aldehyde complex [Fe(C14H11N2O3)2(H2O)2] by MicroED.

The title compound, di-aquabis-{2-formyl-6-meth-oxy-4-[(E)-2-phenyl-diazen-1-yl]phenolato-κ2 O 1,O 2}iron(II), [Fe(C14H11N2O3)2(H2O)2], comprises two bi-dentate ligands derived from 2-meth-oxy-4-(phenyl-diazen-yl)-6-formyl-phenol and two coordinated water mol-ecules. The FeII center is located at a crystallographic inversion center and adopts an octa-hedral coordination geometry. Both azo-phenolate ligands coordinate in a bidentate chelating mode (κ2 O,O') through the phenolate oxygen and formyl oxygen atoms in a centrosymmetric arrangement. The crystal structure was determined at 79 K using the MicroED method (λ = 0.02508 Å). The complex crystallizes in the monoclinic space group P21/n with Z = 2. The azo groups adopt trans conformations. A Hirshfeld surface analysis indicates that the most important contributions to the packing are from H⋯H (36.8%) and C⋯H/H⋯C (31.9%) contacts.