Crystal structure of ethylenediammonium hexaaquanickel(II) sulfate: a variation on the Tutton salts

Abstract

The crystal structure of the title complex, [H₃NCH₂CH₂NH₃] [Ni(H₂O)₆] [SO₄]₂, has been determined by single-crystal X-ray diffraction methods at 295 K, being refined by full matrix least squares to a residual of 0.032 for 2532 independent 'observed' reflections. Crystals are monoclinic, P2₁/n, a 13.148(3), b 7.119(3), c 8.245(2) Å, β 100.97(4)º, Z = 2. Both cations are disposed about crystallographic centres of symmetry. The organic species has a necessarily planar non-hydrogen atom skeleton [C-C, 1.513(3); C-N, 1.485(4) Å]. In the hexaaquanickel(11) species, the Ni-O distances are very similar [2.060(2), 2.064(2), 2.066(2) Å], although there is a significant departure from octahedral symmetry among the angles [89.71(8), 86.87(8), 90.00(8)º]. The oxygen atoms of the water molecules are bonded pseudo-tetrahedrally. The centrosymmetric metal atom environment is more regular than that in the corresponding Tutton salts, to which complexes of the present type may present an attractive alternative.