Diaqua(5,10,15,20-tetraphenylporphinato)iron(III) Perchlorate, [Fe(C44H28N4)(H2O)2]ClO4.

The crystal structure of a new crystal form of [Fe(TPP)(H2O)2]ClO4 has been determined. The asymmetric unit contains one molecule in a general position and a half molecule with required inversion symmetry. The two independent molecules have almost identical average values for the equatorial Fe-Np bond lengths [2.029 (4) and 2.028 (6) A], and the axial Fe-O bond lengths are 2.140 (2) and 2.121 (3) A for molecule 1 (in a general position) and 2.126 (2) A for molecule 2 (in a special position). A brief comparison of the core structure and hydrogen-bonding environment of this molecule with two other crystal forms is described.