Spectrophotometric Study of Cobalt (II) Chlorocomplexes in Methanol in the Visible Domain

Abstract

Cobalt(II) chlorocomplexes were studied in a polar protic solvent namely methanol at 25°C. The spectrophotometric technique in the visible region was used. The studied equilibrium is: Co2+ + j Cl- CoClj ↔ (j-2)-. Formation of three chlorocomplexes and a structural modification (Oh → Td) were obtained from recorded spectra analysis. The stability of CoCl+ was studied by the graphical method of Kruh and the overall stability constants were calculated with the SIRKO program based on the least-square method. Different models were tested and the model was retained for which the best values are: log β1 = 0.92, log β2 = 1.31 and log β3 = 1.08.