Crystal structure of [Ni(OH(2))(6)]Cl(2)·(18-crown-6)(2)·2H(2)O.

The crystal structure of the title compound, hexa-aqua-nickel(II) dichloride-1,4,7,10,13,16-hexa-oxa-cyclo-octa-deca-ne-water (1/2/2), [Ni(H(2)O)(6)]Cl(2)·2C(12)H(24)O(6)·2H(2)O, is reported. The asymmetric unit contains half of the Ni(OH(2))(6) moiety with a formula of C(12)H(32)ClNi(0.50)O(10) at 105†K and triclinic (P1) symmetry. The [Ni(OH(2))(6)](2+) cation has close to ideal octa-hedral geometry with O-Ni-O bond angles that are within 3° of idealized values. The supra-molecular structure includes hydrogen bonding between the water ligands, 18-crown-6 mol-ecules, Cl(-) anions, and co-crystallized water solvent. Two crown ether mol-ecules flank the [Ni(OH(2))(6)](2+) mol-ecule at the axial positions in a sandwich-like structure. The relatively symmetric hydrogen-bonding network is enabled by small Cl(-) counter-ions and likely influences the more idealized octa-hedral geometry of [Ni(OH(2))(6)](2+).