Crystal structures of the [18]-crown-6 ammoniate C12H24O6 center dot 2 NH3 and the cryptand [2.2.2] ammoniate C18H36O6N2 center dot 2 NH3

摘要

The crystal structures of the new polyether ligand-ammoniates C12H24O6 center dot 2 NH3 (1) and C18H36O6N2 center dot 2 NE3 (2) have been elucidated at 123 K by single crystal X-ray structure analysis. Compound 1 crystallizes as yellow plate-like crystals in the monoclinic space group P2(1)/c (no. 14) with unit cell parameters a = 7.572(4) angstrom, b = 7.724(4) angstrom and c = 14.448(7) angstrom with an angle beta = 91.79(6)degrees. It consists of a molecule of [18]-crown-6 to which two ammonia molecules of crystallisation are bound by three hydrogen bonds each. The ammonia molecules reside below and above the plane of the crown ether oxygen atoms. Compound 2 crystallizes as colourless isometric crystals in the space group P6(3)22 (no. 182) with unit cell parameters a = 8.2568(5) angstrom and c = 18.992(2) angstrom. It consists of molecules of cryptand [2.2.2] which are connected by hydrogen bonds via ammonia molecules of crystallisation, resulting in two-dimensional layers parallel to the ab-plane.