Synthesis of new substituted benzaldazine derivatives, hydrogen bonding-induced supramolecular structures and luminescent properties

Syntheses of three benzaldazine compounds 1–3 with the general formula Ar1(CH = N–N = HC)Ar2 (Ar1 = Ar2 = 2-OH-3,5-tBu2C6H2 (1), Ar1 = Ar2 = 2-BrC6H4 (2), Ar1 = ortho-C6H4(NHC6H3-Me2-2,6), Ar2 = C6H4F-2 (3)) are described. All compounds were characterized by elemental analysis, 1H NMR, 13C NMR, IR spectroscopy and single-crystal X-ray crystallography. The different supramolecular structures were obtained through different weak interactions (C − H···O, O − H···N and π···π interactions for 1; C − H···Br and Br···Br interactions for 2; C − H···F and C − H···N interactions for 3). Compound 1 shows solvent-dependent fluorescent properties with blue to green emission on the increasing of the solvent polarity. Compounds 2, 3 show blue photoluminescence in different solvents.