title: 4-[(Dimethyl-amino)methyl-idene]-2-(4-nitro-phen-yl)-1,3-oxazol-5(4H)-one.
abstract: The title mol-ecule, C(12)H(11)N(3)O(4), is essentially planar, the r.m.s. deviation for all non-H atoms being 0.068 Å. An intra-molecular C-H⋯N hydrogen bond occurs. The crystal packing is dominated by π-π inter-actions [shortest centroid-centroid distance = 3.6312 (16) Å], which lead to supra-molecular chains that are linked into a three-dimensional network via C-H⋯O contacts. The crystal was found to be a non-merohedral twin (twin law -1 0 0/0 -1 0/ 0.784 0 1), the fractional contribution of the minor component being approx-imately 22%.
authors.forename: Gilberto A
authors.initials: GA
authors.lastname: Romeiro
authors.forename: Carlos M R
authors.initials: CM
authors.lastname: Ribeiro
authors.forename: Solange M S V
authors.initials: SM
authors.lastname: Wardell
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell
authors.forename: Seik Weng
authors.initials: SW
authors.lastname: Ng
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink