The crystal structure of triaqua(1, 10-diaza-18-crown-6)chlorobarium chlori
de [Ba(DA18C6)Cl(H2O)(3)]Cl-+(-) (I) is studied by X-ray diffraction analys
is: space group Pnma, a = 14.912, b = 13.590, c = 10.456 Angstrom, Z = 4. S
tructure I is solved by the direct method and refined by the full-matrix le
ast-squares method in the anisotropic approximation: R = 0.079 for all 3194
measured independent reflections (CAD-4 diffractometer, lambda MoKalpha).
Crystal I exists as complex guest-host cations and Cl- anions connected via
interionic hydrogen bonds. The cations and anions are located in the in sy
mmetry plane. The Ba2+ ion (coordination number 10) is in the cavity of the
DA18C6 macrocycle acid is coordinated by its six heteroatoms (2N + 40) and
also by the Cl- anion and two O atoms of two water molecules from one side
of the macrocycle and by the O atom of the third water molecule from anoth
er side. The DA18C6 ligand in I has the conformation of a crown with an app
roximate D-3d symmetry.