The investigation of crystal structure, spectroscopic and thermal properties of p-(p-acetylphenylazo)-o-allylphenol and p-(p-bromphenylazo)-o-allylphenol

The two new azo dyes p-(p-acetylphenylazo)-o-allylphenol (compound I) and p-(p-bromphenylazo)-o-allylphenol (compound II) have been synthesized and studied by FT-IR, UV-VIS, 1H NMR, 13C NMR techniques, elemental analysis, X-ray structure analysis and TG, DTG, and DTA analyses. Compound I crystallizes in the monoclinic space group P21/c with a = 19.6130(15) Å, b = 7.3586(6) Å, c = 21.4752(15) Å, α = 90.00°, β = 101.413(6)°, γ = 90.00°, Z = 8, V = 3038.1(4) Å3 and the molecules are linked by two intermolecular O⋯O hydrogen bonds. There are two independent molecules in the asymmetric unit of compound I. Compound II crystallizes in the monoclinic space group Cc with a = 4.7194(7) Å, b = 24.597(2) Å, c = 12.2241(16) Å, α = 90.00°, β = 96.509(11)°, γ = 90.00°, Z = 4, V = 1409.9(3) Å3 and the molecules are linked by O⋯N and C-H⋯O intermolecular hydrogen bonds. They are characterized by UV-VIS, FT-IR, 1H NMR, 13C NMR techniques, elemental analysis, TG, DTG, and DTA analyses.