title: (E)-1-(2,4-Dinitro-phen-yl)-2-pentyl-idenehydrazine.
abstract: The title compound, C(11)H(14)N(4)O(4), is essentially planar with an r.m.s. deviation for the 19 non-H atoms of 0.152 Å. The conformation about the C=N bond is E, and the mol-ecule has a U-shape as the butyl group folds over towards the aromatic system. An intra-molecular C-H⋯N inter-action occurs. The crystal packing is dominated by N-H⋯O hydrogen bonding and C-H⋯O contacts, leading to twisted zigzag supra-molecular chains along the c direction. The crystal packing brings two nitro O atoms into an unusually close proximity of 2.686 (4) Å. While the nature of this inter-action is not obvious, there are several precendents for such short nitro-nitro O⋯O contacts of less than 2.70 Å in the crystallographic literature.
authors.forename: Patrícia D
authors.initials: PD
authors.lastname: Neunfeldt
authors.forename: Auri R
authors.initials: AR
authors.lastname: Duval
authors.forename: Wilson
authors.initials: W
authors.lastname: Cunico
authors.forename: Solange M S V
authors.initials: SM
authors.lastname: Wardell
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell