On the Crystal Structure of K₂Cu₅Cl₈(OH)₄·2H₂O

Abstract

Abstract Single crystals of K 2 Cu 5 Cl 8 (OH) 4 ·2H 2 O were grown using hydrothermal techniques. The compound is monoclinic with a = 11.6424(11), b = 6.5639(4), c = 11.7710(10)Å, β = 91.09(1)°, V = 899.4(2)Å 3 , space group P 2 1 / c , Z = 2. The crystal structure was determined using single crystal X‐ray diffraction data and refined to a residual of R(|F|) = 0.025 for 1208 independent observed reflections with I > 2σ(I). Two out of three crystallographically independent Cu atoms are coordinated to four near hydroxyl groups or chlorine atoms and two more distant Cl atoms, giving an octahedrally Jahn‐Teller distorted (4+2)‐configuration. For the remaining third copper cation a square‐planar coordination can be found. Edge‐sharing of the octahedra results in the formation of kagome ‐type sheets parallel to (100). The octahedral layers are decorated on both sides by planar [Cu(OH) 2 Cl 2 ]‐units around the third Cu atom. The K atoms are located between adjacent sheets and are surrounded by six Cl atoms as well as two water molecules. The coordination polyhedra about the K‐atoms can be described as distorted bicapped trigonal prisms. Additional linkage is provided by intra ‐ as well as inter ‐layer hydrogen bonds (O—H···Cl, O—H···O).