Hemi(piperazinediium) hexaaquaaluminium(III) bis(sulfate) tetrahydrate: a new double aluminium sulfate salt.

Piperazinium aluminium sulfate decahydrate, (C(4)H(12)N(2))(0.5)[Al(H(2)O)(6)](SO(4))(2).4H(2)O, exhibits a crystal structure built from isolated [Al(H(2)O)(6)](3+), SO(4)(2-), C(4)H(12)N(2)(2+) and H(2)O units connected by a complex hydrogen-bond network. The title compound shows strong similarities to many double aluminium sulfates, such as alums and Tutton's salts. However, since its structure is not derived directly from that of these compounds, it is assumed to be a new structure type.