Crystal structure of an ammonium thiocyanate complex of 18crown-6

The title compound (C13H30N2O 7S) has been determined from three-dimensional X-ray diffraction data. The crystals are monoclinic, a = 22.654(8) Å, b = 8.652(4) Å, c = 23.925(9) Å, β= 123.880(9)°, V= 3893(3) Å3, Z = 8, Dcalc =1.192 g/cm3, space group C2/c. The structure was solved by direct methods and refined by full-matrix least squares method (R = 0.051). The ammonium cation is displaced by 1.08 Å from the mean plane of the ligand causing hydrogen bonding with the macrocyclic O atoms in a perching arrangement. The thiocyanate anion forms an extended hydrogen bonded chain with the cation via the occluded water molecule. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.