The (E)-2-acethyl-4-(4-bromophenyldiazenyl) phenol compound was synthesized and analysed by elemental analysis, single-crystal X-ray diffraction (XRD), FT-IR and FT-Raman spectroscopies. Furthermore, vibrational spectra of this compound have been assigned by using scaled quantum mechanical force field approximation from density functional method (B3LYP) with 6-31G(d) basis set. A well-agreement has been attained between the calculated and observed spectra. Moreover, NBO analysis indicates there are strong conjugate interactions inside the molecule. Apart from this, the single-crystal structure from X-ray study has showed that this compound has a strong intramolecular O-H center dot center dot center dot O hydrogen bond and pi - pi stacking. (C) 2015 Elsevier B.V. All rights reserved.