Chloro Complexes of Mercury(II) in Aqueous Perchlorate Media: Equilibrium and Electronic Absorption Spectra

The literature data on the equilibrium constants of formation of HgCl^– _{3 solv} and HgCl^2– _{4 solv} from HgCl_{2 solv} and Cl^– _solv in aqueous perchlorate–chloride solutions were generalized. The individual electronic absorption spectrum of the trichloro complex of mercury(II) was obtained for the first time, and the effect of the ionic strength on the spectra of di-, tri-, and tetrachloro complexes of mercury(II) was considered. The previously developed procedures for the resolution of absorption spectra into individual bands were found to be suitable for interpretation of spectral changes experimentally observed for solutions as the result of stepwise complexation. The parameters of the absorption bands in the spectra of chloro complexes of mercury(II) were determined.