The Fe3O4 magnetic nano‐particles were modified with 1,10‐phenanthroline‐5,6‐diol and the relevant Mn complex (Fe@Phendiol@Mn) synthesized as a nano‐magnetic heterogeneous catalyst to be used for the synthesis of various arylaminotetrazoles from various arylcyanamides and sodium azide in DMF at 120 °C. Also, the nano‐catalyst characterized by different methods such as the elemental analysis (CHN), ICP, FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA, VSM and XPS. In addition, the theoretical study of the Fe@Phendiol@Mn nano‐catalyst was performed using the Gausian software. The calculated results showed that the Gibbs free energy and the standard enthalpy values are negative; therefore the complex is stable. Incidentally, the computational chemistry descriptions including the electronic chemical potential, global hardness, electrophilicity index, energy gap, global softness and electronegativity were calculated.
