Abstract
The synthesis of two derivatives (sodium methyldodecylphosphonate) A and (sodium methyl (11-methacryloyloxyundecyl) phosphonate) B was performed using the methods described by (Yactine et al. 2005; Senhaji et al. 2004). After purification, the compounds obtained are characterised. The inhibitory effect on the corrosion of the two derivatives A and B has been study using weight loss measurements. Results obtained show that the compound B is found the best inhibitor and its inhibition efficiency (E %) reached up to 90% for 5 x 10(-4) M of B. On the other hand and in order to determine the relationship between the molecular structure of these compounds and inhibition efficiency, quantum chemical parameters such as the highest occupied molecular orbital energy (E-HOMO), the lowest unoccupied molecular orbital energy (E-LUMO), energy gap (Delta E), dipole moment (mu), electronegativity (chi), electron affinity (A), global hardness (eta), softness (sigma), ionization potential (I), the fraction of electrons transferred (Delta N), and the total energy (TE), were calculated. The theoretically obtained results were found to be consistent with the experimental data reported.