Ternary Hydroxides II. Synthesis and Crystal Structure of the Layered Barium Hexahydroxidostannate(IV) Pentahydrate, Ba[Sn(OH)6]·5H2O 

Abstract Single crystals of Ba[Sn(OH) 6 ]·5H 2 O ( 1 ) were grown by three different methods and the crystal structure was determined by X‐ray diffraction (monoclinic, P 2 1 / c , a = 10.3119(2) Å, b = 8.6079(2) Å, c = 23.4906(4) Å, β = 90.774(1)°, V = 2084.93(7) Å 3 , Z = 8). The fundamental primary building units (PBU′s) consist of two octahedral [Sn(OH) 6 ] 2– ions and two monocapped square antiprisms of {Ba(OH) 4 (H 2 O) 5 }. The latter and one of the two {Sn(OH) 6 } octahedra are linked together through common edges resulting in the formation of layers, the secondary building units (SBU′s). These layers can be described in terms of two {BaO 9 } Zweier single chains parallel to the b axis which are linked together every second antiprism through common edges with one of its two adjacent chains. The holes between these chains are filled from the {Sn(OH) 6 } octahedra. In contrast, the second {Sn(OH) 6 } octahedron has the function of a spacer separating the SBU′s from each other. Furthermore, the interlayer space is filled by five additional water molecules which are not part of any coordination sphere. All building units are held together by an extended network of hydrogen bonds with structural data that indicate medium strong to weak interactions.