Kamburov Stoyan, Schmidt Horst, Voigt Wolfgang, Balarew Christo
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. Georgi Bonchev bl. 11, Sofia 1113, Bulgaria.
Institute of Inorganic Chemistry, Technische Universität Freiberg, Freiberg, Germany.
Acta Crystallogr C Struct Chem. 2017 Jul 1;73(Pt 7):582-587. doi: 10.1107/S2053229617009330. Epub 2017 Jun 29.
Metal selenates crystallize in many instances in isomorphic structures of the corresponding sulfates. Sodium magnesium selenate decahydrate, NaMg(SeO)·10HO, and sodium magnesium selenate dihydrate, NaMg(SeO)·2HO, were synthesized by preparing solutions of NaSeO and MgSeO·6HO with different molar ratios. The structures contain different Mg octahedra, i.e. [Mg(HO)] octahedra in the decahydrate and [MgO(HO)] octahedra in the dihydrate. The sodium polyhedra are also different, i.e. [NaO(HO)] in the decahydrate and [NaO(HO)] in the dihydrate. The selenate tetrahedra are connected with the chains of Na polyhedra in the two structures. O-H...O hydrogen bonding is observed in both structures between the coordinating water molecules and selenate O atoms.
许多情况下，金属硒酸盐会以相应硫酸盐的同构结构结晶。通过制备不同摩尔比的Na₂SeO₄和MgSeO₄·6H₂O溶液，合成了十水合钠镁硒酸盐Na₂Mg(SeO₄)₂·10H₂O和二水合钠镁硒酸盐Na₂Mg(SeO₄)₂·2H₂O。这些结构包含不同的镁八面体，即十水合物中的[Mg(H₂O)₆]八面体和二水合物中的[MgO₂(H₂O)₄]八面体。钠多面体也不同，即十水合物中的[Na₂O₂(H₂O)₈]和二水合物中的[Na₂O₂(H₂O)₂]。在这两种结构中，硒酸根四面体与钠多面体链相连。在两种结构中，配位水分子和硒酸根O原子之间均观察到O-H...O氢键。
