Synthesis and crystal structure of (2.2.2-cryptand)potassium nitrate hydrate

(2.2.2-Cryptand)potassium nitrate hydrate, K(Crypt-222)](NO₃) · 1.5H₂O (I) was synthesized and studied by X-ray diffraction method. Crystals I are triclinic (space group P ī, a = 11.262 Å, b = 12.033 Å, c = 12.181 Å, α = 60.48°, β = 86.17°, γ = 66.20°, Z = 2). The structure was solved by the direct method and refined by the full-matrix least-squares method in anisotropic approximation to R = 0.065 from 3377 independent reflections (CAD-4 automated diffractometer, λMoK _α). In complex I, the host-guest complex cation K(Crypt-222)]⁺ has approximate D ₃ symmetry. The coordination polyhedron of the K⁺ cation is a two-base-centered trigonal prism, which is slightly distorted toward antiprism. The disordered NO ₃ ^? anions and water molecules are united by hydrogen bonds into infinite chains along the x-axis.