Analytical, Spectral, Thermal and Molecular Modeling Studies of Hg2+-2,3-Butanedionemonoxime Girard’s T Hydrazone Complex and Its Application

The coordination behavior of 2,3-butanedionemonoxime Girard’s T hydrazone (L1) towards Hg2+ ion has been investigated. The structure of Hg2+ complex, [Hg(L1)Cl]Cl·5H2O, is elucidated using elemental analyses, spectral (IR, UV-visible, 1H-NMR and mass) and TGA measurements. IR spectrum suggests that L1 behaves in a bidentate manner through the azomethine groups. The molecular modeling of L1 and its Hg2+ complex has been investigated. The bond lengths, bond angles, HOMO and LUMO have been calculated. The thermal behavior and kinetic parameters are determined using Coats-Redfern method. The use of L1 for preconcentration and separation via flotation of Hg2+ complex and determination using cold vapor atomic spectrometry (CVAAS) is described. The effects on the percentage of recovered Hg2+ by pH of sample solutions, oleic acid (HOL) concentration, Hg2+ and L1 concentrations are studied in details. The method is applied for the determination of the total Hg2+ (mg·mL-1) in natural water samples.