Synthesis and spectroscopic studies of some new ortho functionalized triazene compounds and their reactivity with mercury (II) ion

In this work, a series of triazene derivatives in which the substituents have a wide range of electronic characters were synthesized to understand the effect of the substituent identity in controlling the changes in their electronic absorption spectra and NMR chemical shifts, as well as their tendency for interaction with some heavy metals. Elemental analysis and ¹H NMR, ¹³C NMR, and FT-IR spectroscopies were used to elucidate the chemical structures of the new compounds. Thermal analysis and protolysis of these triazenes were evaluated. The thermodynamic parameters were calculated from thermal data using Coats-Redfern method. Complexation of these compounds with mercury (II) ion in acetonitrile and deuterated dimethylsulfoxide (DMSO-d₆) solution were studied by UV–vis and ¹H NMR spectroscopy, respectively. Stoichiometry and formation constants of the complexes were calculated by the mole ratio titration method. The effects of the nature of the substituents on the formation constants were discussed.