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

Abstract: 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 150K, a =10.4505(2), b =8.0358(2), c =11.3208(2)Å, β =102.56(2)°, Z =2, V =927(9)Å3, Dx =1.618gcm−3, refinement on 2217 reflections, R =0.023. For the chloro derivative at 150K, a =10.3416(8), b =8.0605(5), c =11.1573(8)Å, β =102.70(8)°, Z =2, V =907(3)Å3, Dx =1.330gcm−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 CBr or Cl contacts. There are no Cl⋯N or Br⋯N interactions. [Copyright &y& Elsevier]