title: A re-examination of supramolecular aggregation in two polymorphs of acetone 2,4-dinitrophenylhydrazone.
abstract: The structure of the triclinic polymorph of acetone 2,4-dinitrophenylhydrazone, C(9)H(10)N(4)O(4), has been redetermined from diffraction data collected at 120 (2) K; the molecules are linked by C-H...O hydrogen bonds into centrosymmetric R(2)(2)(10) dimers which are themselves linked into a chain by an aromatic pi-pi stacking interaction. In the monoclinic polymorph, which crystallizes with Z' = 2 in the space group P2(1)/n, one type of molecule forms dimers exactly as in the triclinic polymorph, while the other forms C(6) chains.
authors.affiliation: Instituto de Química, Departamento de Química Inorgânica, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro, RJ, Brazil.
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell
authors.forename: R Alan
authors.initials: RA
authors.lastname: Howie
authors.forename: John N
authors.initials: JN
authors.lastname: Low
authors.forename: Christopher
authors.initials: C
authors.lastname: Glidewell