Tetrel, halogen and hydrogen bonds in bis(4-((E)-(2,2-dichloro-1-(4-substitutedphenyl)vinyl)diazenyl)phenyl)methane dyes

Reaction of bis(4-hydrazinylphenyl)methane with 4-substitutedbenzaldehyde in the presence of CH3COONa in EtOH at 80 °C yields bis(4-((E)-2-(4-substitutedbenzylidene)hydrazinyl)phenyl) methane [−N(CH3)2 1, −F 2, −Cl 3, −NO2 4], which subsequently in the presence of CCl4, CuCl and tetramethylethylenediamine in DMSO undergoes Cu-catalyzed olefination products, bis(4-((E)-(2,2-dichloro-1-(4-substitutedphenyl)vinyl)diazenyl)phenyl)methane [−N(CH3)2 5, −F 6, −Cl 7, −NO2 8], respectively. All compounds were characterized by IR (for 1–4), 1H and 13C NMR spectroscopies, elemental and X-ray diffraction analysis (for 7 and 8). No only intermolecular hydrogen and intramolecular N⋯Cl tetrel bonds, but also the Cl⋯Cl and Cl⋯O types of halogen binding were found in the structures of 7 and 8, respectively. The collected data confirm that bis-azodyes 5–8 exist in DMSO solution and in solid state exclusively in the E-isomeric form, being stabilized by noncovalent interactions. Solvent effects on the UV–vis absorption spectra of 5−8 were studied in CH2Cl2, DMF and EtOH, which λmax is dependent on the type of substituents attached para-position of aromatic moiety. © 2017 Elsevier Ltd