Copper and manganese sulfanilate hydrates

The title compounds, bis(4-aminobenzenesulfonato)-diaquacopper(II) dihydrate, [Cu(C₆H₆NO₃S)₂(H₂O) ₂].-2H₂O, and bis(4-aminobenzenesulfonato)diaquamanganese(II), [Mn(C₆H₆NO₃S)₂(H₂O) ₂], have structures in which the sulfanilate anions are arranged in layers with the functional groups directed towards adjacent layers. Between these slabs are the metal cations and water molecules. The Cu atom sits in a tetragonally distorted octahedron, with short contacts to two amine N atoms and two water molecules. Two sulfonate O atoms provide the longer interactions. The other water molecules are anchored by hydrogen bonds to the sulfonate groups. The Mn atom also displays a tetragonal distortion of its octahedral coordination to two sulfonate O atoms, two water molecules and, at the elongated vertices, two amine N atoms. The manganese salt contains no free water molecules. Both structures differ from those of the reported cobalt and zinc salts.