The present investigation focuses on the geometrical optimized parameters, IR and raman activity based on vibrational frequencies, and global reactivity descriptors of mesogens namely; para-azoxyanisole (PAA), ethyl para-azoxybenzoate (EPAB) and non-mesogen biphenyl-4-carboxylic acid (BCA) molecules via the Density functional theory (DFT) and Hartree–Fock (HF) technique accompanied with 6–31++G (d, p) basis set. The wavenumbers/frequencies obtained for utmost of the vibrational modes are in the predicted range but with minimal error. Reactivity of these molecules based on the molecular properties viz., HOMO, LUMO energies, ionization potential, electro negativity, chemical potential, electron affinity, chemical hardness, and softness has also been focused. The DFT method considers all different electronic interactions thereby give accurate results as compared to Hartree–Fock method. The azoxy bond plays an important role in chemical bond formation in liquid crystals, chemical intermediates, process control, and pharmaceuticals etc. Further, the estimated band gap values indicate the understanding of fine tuning mechanism for exploring the possible industrial applications. Graphical Abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.