Crystal structures and characterization of two divalent metal selenates templated by dabco, (C6H14N2)[MII(H2O)6](SeO4)2 (MII: NiII, ZnII)

International audienceTwo new organic-inorganic hybrid materials have been synthesized and crystallographically characterized. Both compounds, (C6H14N2)[Ni(H2O)6](SeO4)2 (I) and (C6H14N2)[Zn(H2O)6](SeO4)2 (II), crystallize isotypically in the monoclinic system, space group P21/c, with the following unit cell parameters: a = 12.4045(3), b = 11.9360(3), c = 12.8366(3) Å, β = 108.518(2)°, V = 1802.18(8) Å3, Z = 4 for compound (I) and a = 12.7839(2), b = 11.9153(4), c = 12.3814(2) Å, β = 108.264(5)°, V = 1790.97(7) Å3, Z = 4 for the zinc related phase. Their supramolecular structure consists of metallic cation octahedrally coordinated by six water molecules [MII(H2O)6]2+, selenate anions (SeO4)2- and dabcodiium cation (C6H14N2)2+ linked together via two types of hydrogen bonds, Ow-H...O and N-H...O only. The thermal decomposition of these supramolecular compounds takes place in several steps leading to the formation of metal oxide. The magnetic measurements show that the nickel based compound is predominantly paramagnetic with weak antiferromagnetic interactions at low temperature