Crystal structure and Hirshfeld surface analysis of (E)-2-[1-hy-droxy-2-(pyridin-2-yl)eth-yl]-4-[2-(4-meth-oxy-phen-yl)diazen-1-yl]phenol.

In the title compound, C20H19N3O3, the configuration about the azo N=N bond is E, and the central benzene ring is inclined to the pyridine ring by 31.43 (8)° and to the 4-meth-oxy-phenyl ring by 4.73 (8)°. In the crystal, mol-ecules are linked by pairs of O-H⋯N hydrogen bonds, forming inversion dimers with an R 2 2(12) ring motif. The dimers are linked by O-H⋯O and C-H⋯O hydrogen bonds, forming layers parallel to the ac plane. There are C-H⋯π inter-actions present within the layers and between the layers, leading to the formation of a supra-molecular framework. The layers are also linked by offset π-π inter-actions, with an inter-planar distance of 3.416 (2) Å.