Synthesis and Crystal Structure of Dibenzo-18-crown-6 Oxonium Perchlorate Trihydrate

摘要

A hydrated crystalline ionized adduct of dibenzo-18-crown-6 and perchloric acid DB18C6 centre dot H_3O~+ centre dot CiO_4 centre dot 3H_9O (I) is synthesized and characterized by X-ray diffraction. The crystals of I are monoclinic: a =17.760 A, b = 13.311 A, c = 12.922 A, P = 124.27 deg, Z = 4, space group Cc. The structure of I is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.079 for 3294 independent reflections (CAD4 automated diffractometer, gamma MoK_a radiation). A DB18C6 molecule has a butterfly conformation with the rough symmetry C2v- An H_3O~+ centre dot H_2O dimer is situated on one side of the DB18C6 macrocycle, and the ClO_4 anion and two other water molecules are on the other side. In the crystal of I, the DB18C6 molecules, H_3O~+ and CIO4 ions, and water molecules are linked through intermolecular (interionic) hydrogen bonds to form broad infinite chains running along the z axis.