Crystal structure of a polymorph of μ-oxido-bis[(5,10,15,20-tetraphenylporphyrinato)iron(III)]

The title compound, [Fe-2(C44H28N4O)(2)O], was obtained as a by-product during the synthesis of Fe-III tetraphenylporphyrin perchlorate. It crystallizes as a new polymorphic modification in addition to the orthorhombic form previously reported [Hoffman et al. (1972). J. Am. Chem. Soc. 94, 3620-3626; Swepston & Ibers (1985) Acta Cryst. C41, 671-673; Kooijmann et al. (2007). Private Communication (refcode 667666). CCDC, Cambridge, England]. In its crystal structure, the two crystallographically independent Fe-III cations are coordinated in a square-planar environment by the four N atoms of a tetraphenylporphyrin ligand. The Fe-III-tetraphenylporphyrine units are linked by a mu(2)-oxido ligand into a dimer with an Fe-O-Fe angle close to linearity. The final coordination sphere for each Fe-III atom is square-pyramidal with the mu(2)-oxido ligand in the apical position. The crystal under investigation consisted of two domains in a ratio of 0.691 (3): 0.309 (3).