Crystal structure of diaqua[5,10,15,20-tetrakis(4-bromophenyl) porphyrinato-κ4 N]magnesium

Abstract

The title compound, [Mg(C44H24Br4N4)(H2O)2] or [Mg(TBrPP)(H2O)2], where TBrPP is the 5,10,15,20-tetra-kis(4-bromophenyl) porphyrinato ligand, was obtained unintentionally as a by-product of the reaction of the [Mg(TBrPP)] complex with an excess of dimethylglyoxime in dichloro-methane. The entire molecule exhibits point group symmetry 4/m. In the asymmetric unit, except for two C atoms of the phenyl ring, all other atoms lie on special positions. The MgII atom is situated at a site with symmetry 4/m, while the N and the C atoms of the porphyrin macrocycle, as well as two C atoms of the phenyl ring and the Br atom lie in the mirror plane containing the porphyrin core. The H atoms of the axially bonded water molecule are incompatible with the fourfold rotation axis and are disordered over two sites. In the crystal, molecules are packed in rows along [001]. Weak intermolecular C - H⋯π and C - H⋯Br interactions, as well as O - H⋯Br hydrogen bonds, stabilize the crystal packing.