Supramolecular organization of bis(3-halo-4-dimethylaminobenzylidene)hydrazines

Bis(3-bromo-4-dimethylaminobenzylidene)hydrazine and bis(3-chloro-4-dimethylaminobenzylidene)hydrazine have been synthesized, and their monoclinic crystal structures solved in space group P21/c. For the bromo derivative at 150 K, a = 10.4505(2), b = 8.0358(2), c = 11.3208(2) Å, β = 102.56(2)°, Z = 2, V = 927(9) Å3, Dx = 1.618 g cm−3, refinement on 2217 reflections, R = 0.023. For the chloro derivative at 150 K, a = 10.3416(8), b = 8.0605(5), c = 11.1573(8) Å, β = 102.70(8)°, Z = 2, V = 907(3) Å3, Dx = 1.330 g cm−3, refinement on 2429 reflections, R = 0.038. The molecules are close to planar, the crystal packing shows Br⋯Br or Cl⋯Cl intermolecular halogen bonds, and some CH⋯Br or Cl contacts. There are no Cl⋯N or Br⋯N interactions.

► Two halogenated benzaldimines were synthesized.
► Single crystal structures were determined to study the supramolecular interactions.
► The synthons form one-dimensional chains through halogen–halogen bonds, and no halogen–nitrogen bonds are present.