Iron, (N-(6-methyldipyrido(1,2-a:3',2'-d)imidazol-2-yl)-4,19-dioxo-N'-(4-(10,15,20-tris(4-methylphenyl)-21H,23H-porphin-5-yl)phenyl)-5,9,14,18-tetraazadocosanediamidato(2-)-N21,N22,N23,N24)-, (SP-4-2)-