Crystal and molecular structure of cerium (4) nitrate dihydrate with dicyclohexyl-18-crown-6 (isomer A)

Crystal structure of [(H3O, H2O)4(DCH-6)4]x[Ce(NO3)6]xH2O (crystals of light-yellow colour, a=15.510(4), b=14.973(3), c=13.456(3) A, α=71.53(2), β=94.41(2), γ=68.86(2) deg, sp. gr. P anti 1) has been determined. The structure is resolved using the heavy atom method and is refined in an anisotropic approximation up to R=0.080. The crystal is built of [(H3O, H2O)(DCH-6)]+ complex cations, [Ce(NO3)6]2- anions and crystallization molecules of water. The coordination polyhedron of cerium presents an icosahedron, formed by bidentate nitrogroups. Molecules of H2O and H3O+ are distributed statistically and are bound with DCH-6 via hydrogen bonds. The X-ray powder diffraction data show that, while complexing with DCH-6 in an acid medium, a cerium atom does not form coordination bonds with the ether atoms of the macrocycle