Crystal structures of molecular complexes of 18-crown-6 with 2-aminobenzoic and 5-amino-1-benzyl-1,2,3-triazole-4-carboxylic acid hydrazides

The crystal structures of two host-guest molecular complexes of 18-crown-6 with 2-aminobenzoic acid hydrazide monohydrate (the ratio host : guest : H2O = 1 : 2 : 2) (complex I) and 5-amino-1-benzyl-1,2,3-triazole-4-carboxylic acid hydrazide (the host guest ratio = 1 2) (complex 11) are determined by X-ray diffraction analysis. Crystals I are monoclinic, a 8,468(2) Angstrom, b = 17.378(3) Angstrom, c = 10.517(2) Angstrom, beta = 96.88(3)degrees, space group P2(1)/n, and R = 0.0393 for 6692 reflections. Crystals II are orthorhombic, a = 18.489(1) Angstrom, b = 10.192(3) Angstrom, c = 20.412(2) Angstrom, space group Pbca, and R = 0.0540 for 3513 reflections. In both complexes, the centrosymmetric 18-crown-6 and guest molecules are joined together through the (NHO)-O-...(crown) hydrogen bonds, which involve all the hydrogen atoms of the hydrazine group. The (NHO)-O-...=C intramolecular hydrogen bond is observed in the guest molecule. In structure 1, the water molecule serves as a bridge between the guest molecules related by the glide-reflection plane and combines the guest-host-guest complexes into layers. In structure 11, the guest molecules are linked into chains through hydrogen bonds of the (NHO)-O-...=C type; in turn, the chains composed of guest molecules and the crown ether molecules bonded to these chains form a layered structure. (C) 2002 MAIK "Nauka/Interperiodica".