Synthesis and Crystal Structure of a New Non-Centrosymmetrical Layered Barium Iodide-Thiocyanate Tetrahydrate Ba(SCN)I·4H₂O

Single crystals of a new acentric barium iodide-thiocyanate tetrahydrate Ba(SCN)I·4H₂O (1) are prepared by the isothermal evaporation of aqueous solutions containing Ba(SCN)₂·3H₂O and BaI₂·2H₂O in the 1:1 molar ratio. The crystal structure of 1 is determined by XRD. The substance crystallizes in the orthorhombic unit cell, the I2mb space group, a = 7.4803(2) Å, b = 16.0959(4) Å, c = 24.0037(5) Å. The crystal motif is pseudo-layered and is formed by a packing of two types of layers, cationic and anionic ones, parallel to (010). The cationic layer is composed of distorted [BaS₂N₂(H₂O)₆] face-sharing 10-vertex polyhedra forming zigzag chains along the [100] axis. The neighboring chains are combined into a layer through common vertices corresponding to sulfur atoms. The anionic layer is formed by iodine atoms combined with the cationic layer into a 3D framework by O–H⋯I hydrogen bonds.