Danil de Namor, A.F.; Al Hakawati, N. Anion Complexation by an Azocalix[4]arene Derivative and the Scope of Its Fluoride Complex Salt to Capture CO2 from the Air. Molecules2023, 28, 6029.
Danil de Namor, A.F.; Al Hakawati, N. Anion Complexation by an Azocalix[4]arene Derivative and the Scope of Its Fluoride Complex Salt to Capture CO2 from the Air. Molecules 2023, 28, 6029.
Danil de Namor, A.F.; Al Hakawati, N. Anion Complexation by an Azocalix[4]arene Derivative and the Scope of Its Fluoride Complex Salt to Capture CO2 from the Air. Molecules2023, 28, 6029.
Danil de Namor, A.F.; Al Hakawati, N. Anion Complexation by an Azocalix[4]arene Derivative and the Scope of Its Fluoride Complex Salt to Capture CO2 from the Air. Molecules 2023, 28, 6029.
Abstract
A newly synthesized upper rim azocalix[4]arene, namely, 5,11,17,23-tetra[(4-ethylacetoxyphenyl) (azo)]calix[4]arene, CA-AZ was fully characterized and its chromogenic and selective properties for anions are reported. The receptor is selective for the fluoride anion and its mode of interaction in solution is discussed. The kinetics of the complexation process was found to be very fast as reflected in the immediate color change observed with a naked eye resulting from the receptor-anion interaction. Emphasis is made about the relevance in selecting a solvent in which the formulation of the process is representative of the events taking place in the solution. The composition of the fluoride complex investigated by UV/VIS spectrophotometry, conductance measurements and titration calorimetry was 1:1 and the thermodynamics of complexation was determined. The fluoride complex salt was isolated, and a detailed investigation was carried out to assess its ability to remove CO2 from the air. Recycling of the complex was easily achieved. Final conclusions are given.
Chemistry and Materials Science, Physical Chemistry
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