A New Nickel Selenate Templated by Piperazine: Chemical Preparation, Crystal Structure, Thermal Decomposition, and Magnetic Properties. -Single crystals of (H 2pip)[Ni(H2O)6](SeO4)2 (pip: piperazine) are prepared by slow evaporation of an aqueous solution of NiCO3, piperazine, and H2SeO4 in a 1:1:2 molar ratio. The compound is characterized by single crystal XRD, IR spectroscopy, and magnetic measurements. It crystallizes in the monoclinic space group P2 1/c with Z = 2. Its supramolecular structure consists of isolated [Ni(H 2O)6] 2+ and (H2pip) 2+ cations and (SeO4) 2anions linked together by a three-dimensional network of hydrogen bonds. The compound is predominantly paramagnetic with weak antiferromagnetic interactions at low temperature. -(NKHILI, N. L.; REKIK*, W.; NAILI, H.; Monatsh. Chem. 145 (2014) 6, 931-936, http://dx.