Spectroscopic study of Hg (II)-complex with 4-(dimethylamino)benzaldehyde 4-ethylthiosemicarbazone

This study reported on a newly synthesized Hg (II)-thiosemicarbazone complex. The complex was characterized using uv-visible spectrophotometry. The mercury (II) - 4-(Dimethylamino)benzaldehyde 4-ethylthiosemicarbazone (DMABET) in methanol had a maximum absorbance (λmax) at 374 nm, whereas the λmax for DMABET in methanol was 356 nm. At optimum pH i.e. pH 4 λmax had shifted to 381 nm. The molar stoichiometry of the complex obtained by the Job's and mole ratio methods was Hg: DMABET = 1: 4. It was found from Job's method data that the stability constant of Hg(II)-DMABET complex is 9.24×106 and ΔG = -9.55 Kcal/mol at 25 ± 2°C.