Some triazole derivatives (4-amino-5-mercapto-3-methyl 1,2,4-triazole (AMMT), 4-amino-5-mercapto-3-ethyl 1,2,4-triazole (AMET) and 4-amino-5-mercapto-3-propyl 1,2,4-triazole (AMPT)) have been evaluated as new corrosion inhibitors for the corrosion of muntz alloy (60Cu-40Zn) in acidic and neutral solutions. The adsorption of these compounds has been tested thermodynamically which was found to be of a physisorption mode. Furthermore, some activation thermodynamic parameters such as Delta H*, Delta S* and Delta G* of activation have been estimated. In addition, a trial to find a quantitative relationship between the inhibition efficiency and the electronic properties of the inhibitor molecules was carried out. (c) 2006 Elsevier B.V. All rights reserved.