Azobased iminopyridine ligands and their rhenium metal complexes: Syntheses, spectroscopic, trans-cis photoisomerization and theoretical studies

•Two rhenium metal complexes have been prepared and structurally characterized.•Absorption spectra have been measured.•DFT calculations have been performed to support the experimental results.•Photoisomerization studies of the azo group in the ligands and in the metal complexes have been performed.