(2,3,7,8,12,13,17,18-Octa-ethyl-porphyrinato-κ(4)N)cobalt(II)-2-nitro-benzaldehyde (1/2).

The asymmetric unit of the title compound, [Co(C(36)H(44)N(4))]·2C(7)H(5)NO(3), is composed of one half of the complex, arranged about an inversion center, and a complete 2-nitro-benzaldehyde (NBA) mol-ecule. The structure consists of columns that contain inter-leaved mol-ecules of NBA and [Co(II)(OEP)] (OEP is 2,3,7,8,12,13,17,18-octa-ethyl-porphyrin), which are stacked along the a axis. The Co(II) atom is involved in a π inter-action with the ring of the NBA mol-ecule with a centroid-metal distance of 3.508 (6) Å. There is an intra-molecular C-H⋯O hydrogen bond in the NBA mol-ecule.