Hydrothermal synthesis, structure and thermal property of a 2-dimensional network: sodium sulfate [Ni(H2O)6(NaSO4)2]

Abstract

The title compound of [Ni(H 2 O) 6 (NaSO 4 ) 2 ] has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallizes in space group P2 1 /c of the monoclinic system in a cell at 293.2 K of a = 6.1820(12) Å, b = 12.316(3) Å, c = 9.0890(18) Å, β = 106.03(3) • , and V = 665.1(2) Å 3 . In the title compound, each SO 4 tetrahedron coordinates with three Na(I) ions and each Na(I) connects to three SO 4 tetrahedrons. Such a coordinate model makes up a two-dimensional network having two different kinds of rings and, in the bigger rings, the [Ni(H 2 O) 6 ] 2+ ions are located. In the solid state, some hydrogen bonds connect the title compound to form three-dimensional networks, stabilizing the crystal structure. Thermogravimetric analysis shows that there are three steps of weight loss from the beginning of 110 • C and the residue may be the mixtures of NiO 2 and Na 2 O.

On the (non-)existence of Tutton salts with formula types [M(H2O)6](ClO4)2(H2O)2and Na2M(SO4)2(H2O)6(Mis a first-row transition metal)

“…Therefore, it is desirable that the deposition of structure factors, or even original intensity (raw) data becomes mandatory in general, irrespective of what scientific journal is chosen for publication of the results of a crystal structure analysis. Although for the other three reported Tutton salts with compositions [Ni(H 2 O) 6 ](ClO 4 ) 2 (H 2 O) 2 (Staples et al, 1998), Na 2 Ni(SO 4 ) 2 (H 2 O) 6 (Zhao et al, 2006) and Na 2 Co-(SO 4 ) 2 (H 2 O) 6 (Lu et al, 2009), rerefinements based on original intensity data were not possible, the same crystalchemically driven arguments as for the two test cases are valid. The too-long Cl-O distances of the ClO 4 tetrahedron, as well as the very unusual environment of the Na + site on the M I position resulting in very low bond-valence sums, make all these structure models dubious.…”

“…During a close examination of the structure family of Tutton salts, some exceptional members were noticed, because they differ substantially from the characteristic chemistry. This includes the perchlorate compounds [Cu(H 2 O) 6 ](ClO 4 ) 2 -(H 2 O) 2 (Li et al, 2004) and [Ni(H 2 O) 6 ](ClO 4 ) 2 (H 2 O) 2 (Staples et al, 1998), as well as the sodium-containing compounds Na 2 Ni(SO 4 ) 2 (H 2 O) 6 (Zhao et al, 2006), Na 2 Co(SO 4 ) 2 (H 2 O) 6 (Lu et al, 2009) and Na 2 Cu(SO 4 ) 2 (H 2 O) 6 (Wu et al, 2008). Table 1 compiles lattice parameters and other structural data of these compounds.…”

Interplay of thermochemistry and Structural Chemistry, the journal (volume 17, 2006) and the discipline

“…The next study by Zhao et al [288] reports on the hydrothermal synthesis and characterization of a twodimensional network of a complex sodium sulfate [Ni(H 2 O) 6 (NaSO 4 ) 2 ] initiated because of a remarkable variety of open-framework inorganic materials reported over the last 10 years [289]. The results show that each SO 4 tetrahedron coordinates with three Na(I) ions and each Na(I) connects to three SO 4 tetrahedrons and that in the solid state hydrogen bonds connect the compound to form a three-dimensional network, stabilizing the crystal structure.…”

Structural and thermal properties of Na2Mn(SO4)2·4H2O and Na2Ni(SO4)2·10H2O

“…[21][22][23] In the system Na 2 Ni(SO 4 ) 2 $nH 2 O three phases are known (n ¼ 0, 4 and 6), however they were not tested as positive electrode materials for NIBs. [24][25][26] For these reasons we prepared recently several Na 2 M(SO 4 ) 2 $nH 2 O phases (M ¼ Mn and Ni) in order to test their electrochemical performances in NIBs.…”