Studies on coordination environment of transition metal chloride anionic speciation of N, N-disulfodiisopropylammonium ionic salts and assessment of their Brønsted-Lewis acidic properties

Abstract

Four ionic salts of N, N-disulfodiisopropylammonium cation with complex anionic speciation of metal chlorides such as [FeCl₄]^-, [NiCl₄]^2-, [Zn₂Cl₆]^2-/[Zn₄Cl₁₀]^2-, [CoCl₄]^2-/[CoCl₃]^-have been synthesized and characterized with FTIR, NMR, TGA, Raman and electronic spectra. Comparative Brønsted and Lewis acidic strength of the salts have been assessed for catalytic uses in organic reactions <em>via</em> UV-visible Hammett plot and FTIR spectra using pyridine as probe molecule. Band gap values obtained from Tauc plot present their semiconductor behavior to design ionic liquid-based photo catalysts in future.