Extraction Properties of Calix[4]arenes towards Sulphonated Dyes

Abstract

Extraction of sulphonated dyes through supramolecular interaction with calix[4]arene derivatives is being presented here. The selectivity of calixarene derivatives namely piperidine derivative of calix[4]arene (calix-1), 1-methyl piperazine derivative of calix[4]arene (calix-2), and di-methyl amine derivative of calix[4]arene (calix-3) were evaluated initially against reactive red 2 (RR-2), acid black (AB), reactive blue 19 (B-19) and synthetic dye (D-2) by liquid-liquid extraction experiment. The results showed that the above three calixarenes possess excellent complexation abilities toward the selected dyes. The stoichiometric ratio for the calixarene derivatives and dyes was estimated through Job’s plot, whereas Hildebrand-Benesi equation was used to calculate formation constant (K s ) and molar absorptivity (Δ ε ) of complexes. The binding association (K a ) and dissociation (K d ) constants were calculated by Scatchard plot additionally to further support the complexation data obtained from Hildebrand-Benesi equation. Conversely association constants from, both Hildebrand-Benesi equation and Scatchard plot i.e. K s and K a favor strong binding interaction between calix-1: D-2, calix-2: B-19, and calix-3: AB complexes. Thus present study adeptly supports the complexation of calixarene derivatives for sulfonated dyes.