title: Monoclinic and orthorhombic polymorphs of 4,4',6,6'-tetrachloro-2,2'-(piperazine-1,4-diyldimethylene)diphenol.
abstract: The title compound, C(18)H(18)Cl(4)N(2)O(2), crystallizes as monoclinic and orthorhombic polymorphs from CHCl3-CH(3)OH solution. In both polymorphic forms, the molecule lies on a crystallographic centre of inversion (at the piperazine ring centroid) and exhibits an intramolecular O-H...N hydrogen bond. In the monoclinic polymorph (space group P2(1)/c), the molecules are linked by intermolecular C-H...Cl hydrogen bonds into a ribbon sheet built from R8(8)(34) rings. In the orthorhombic polymorph (space group Pbcn), the molecules are linked by intermolecular C-H...O hydrogen bonds into a ribbon sheet of R6(6)(34) rings. The sheets in the orthorhombic polymorph are crosslinked into a three-dimensional framework by pi-pi stacking interactions.
authors.affiliation: Division of Natural Science, Osaka Kyoiku University, Kashiwara, Osaka 582-8582, Japan. kubono@cc.osaka-kyoiku.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Kubono
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Yokoi
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry*; D002733:Chlorophenols / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D010879:Piperazines / Q000737:chemistry*; D013314:Stress, Mechanical
chemical_list: C524198:4,4',6,6'-tetrachloro-2,2'-(piperazine-1,4-diyldimethylene)diphenol; D001713:Biphenyl Compounds; D002733:Chlorophenols; D010879:Piperazines