•The study analysed 16 new non-symmetric dimers and confirmed their structures.•All the dimers showed enantiotropic mesophase with a pronounced odd-even effect.•Nematic phase stability was influenced by spacer length.•cis-trans photoisomerization was observed.•Computational analysis provided insights into the dimers' electronic structure. The synthesis and properties of two new mesogenic homologous series comprising of sixteen unsymmetrical dimers of cyanoazobenzene and azo/azomethine naphthalene are described. Their right structure was confirmed by FT-IR, 1HNMR , 13CNMR , and elemental analysis. On the polarising optical microscope (POM), their thermotropic properties were examined and further confirmed using differential scanning calorimetry (DSC). All sixteen dimers exhibit an enantiotropic nematic phase. The relationship between the nematic-isotropic transition temperature and the structures of dimers was discussed. A view of their photochromic behaviour was gained by UV–visible spectroscopy. The 6–31 g (d, p) basis set is combined with the B3LYP functional, which is used for computational studies of all the dimers. The examination of Electrostatic Potential (ESP) and optical characteristics also yielded important information about the electronic structure. Display omitted