New heterocyclic azo derivatives were synthesized by free catalyst reaction. Various techniques such as 1H-NMR, 13C-NMR, and mass spectrometry were used to confirm the structure of the synthesized molecule. The synthesized derivatives have been studied and evaluated as corrosion inhibition for carbon steel in 0.1 M HCl solution. The prepared derivatives 1,1'-(((1E,1'E)-(5-nitro-1,3-phenylene)bis(diazene-2,1-diyl))bis(2-methyl-4,1-phenylene))bis(1H-pyrrole-2,5-dione) (NAH) and 1,1'-(((1E,1'E)-(5-nitro-1,3-phenylene)bis(diazene-2,1-diyl))bis(3-hydroxy-4,1-phenylene))bis(1H-pyrrole-2,5-dione) (NAM) showed 89.22% and 91.30% inhibition efficiencies at a concentration of 1 x 10-3 M, respectively. It is found that the adsorption isotherm of these derivatives conforms to the model of Langmuir. In addition, density functional theory is used to theoretically estimate LUMO, HOMO, and other chemical quantum parameters. The results show that the synthesized derivatives have corrosion inhibitory capabilities, with derivative NAM outperforming derivative NAH. Furthermore, the theoretical results are in line with the experimental data.