Disorder of lattice solvent molecules in the structure of hexaaqua(μ2-1,2,4,5-benzenetetracarboxylato)-bis(2,2’-dipyridylamine)dinickel(II) hexahydrate DMSO solvate

The crystal structure of the complex [Ni2(btc)(dipya)2(H2O)6]⋅6H2O·DMSO (btc = tetra-anion of 1,2,4,5-benzenetetracarboxylic acid, dipya = 2,2’-dipyridylamine) was refined in the triclinic system, space group P1, using low temperature (170 K) X-ray diffraction data. The compound consists of binuclear complex entities and lattice solvent molecules making pseudo-layers parallel to the 101 plane and channels parallel to the b-axis. The observed structural features were compared with the previously reported results and formula [Ni2(btc)(dipya)2(H2O)6]⋅4H2O based on room temperature X-ray diffraction data. A possible arrangement of the disordered lattice solvent molecules located in the structural channels is described and discussed. It is concluded that the layout of these molecules is non-centrosymmetric, although the remaining and main part of the structure is centrosymmetric. .