Abstract:
A novel class of sulphonate group containing unsymmetrical squaraine dyes has been synthesized. These dyes show a selective and sensitive affinity towards Hg2+ in methanol and are practically insensitive to most other environmentally and biologically relevant metal ions. Isothermal titration calorimetric (ITC) studies and High Resolution Mass Spectral (HRMS) analysis indicate a 1:1 binding mode. H-1 and C-13 NMR of the isolated Dye ... Hg2+ adduct showed an unusual addition reaction of Hg2+ along the phenyl-squarate carbon-carbon bond which was also supported by TD-DFT calculations using PM6 level geometries.
