Comparative studies of three isatin-thiosemicarbazones against corrosion of AA6060 aluminum alloy exposed to acidic NaCl medium

•Three new isatin thiosemicarbazones with different substituents (R) were synthesized.•The compounds showed different anti-corrosion efficiency for AA6060 alloy in acidic Cl– medium.•Nature of R imparts substantial effect on the adsorption of inhibitors on alloy surface.•DFT calculation and MD simulation studies substantiate experimental results.•Electron effects of R probably underlie the difference in the inhibition performance.