(2E)-N-(3,5-Dibromo-4-methoxy-phen-yl)-2-(hydroxy-imino)acetamide.

The title compound, C(9)H(8)Br(2)N(2)O(3), is planar (r.m.s. deviation = 0.030 Å) with the exception of the terminal methyl group which lies out of the plane [1.219 (3) Å]. The conformation about the C=N double bond [1.268 (3) Å] is E. An intra-molecular N-H⋯N hydrogen bond occurs. Linear supra-molecular chains along the b axis mediated by O-H⋯O hydrogen-bonding inter-actions feature in the crystal structure. These chains are also stabilized by weak C-H⋯N contacts.

Interplay of hydrogen bonds, iodo...nitro interactions and aromatic pi...pi stacking interactions in iodo-nitroanilines.

Molecules of 2-iodo-5-nitroaniline (I) are linked by N-H...O hydrogen bonds into centrosymmetric dimers and by asymmetric three-centre iodo...nitro interactions into chains, so forming chains of fused centrosymmetric rings: these chains are linked by aromatic pi...pi stacking interactions to form a three-dimensional structure. In the isomeric 4-iodo-2-nitroaniline (II), each of the two independent molecules forms hydrogen-bonded chains that are linked by two-centre iodo...nitro interactions into sheets of two types, each containing only a single type of molecule: pi...pi stacking interactions are absent. In 2,4-diiodo-3-nitroaniline (III), where the nitro group is almost orthogonal to the aryl ring, a combination of N-H...O hydrogen bonds and two distinct two-centre iodo...nitro interactions links the molecules into a three-dimensional framework that is reinforced by aromatic pi...pi stacking interactions. Bond lengths and conformations are discussed and comparisons are drawn with related compounds.