Supramolecular Chemistry On Carbon Dioxide

Abstract

This dissertation describes approaches towards designs, syntheses, characterizations, and applications of supramolecular chemistry on carbon dioxide. Chapter 1 briefly overviews the field of supramolecular chemistry and highlights its horizons, also introduces the progress of sensing devices on chemical warfare agents. Chapter 2 introduces a modular approach to detect chemical warfare agent: phosgene by Fluorescence Resonance Energy Transfer (FRET). It combines the chemical reactivity between amines and phosgene with fluorescence properties of coumarin fluorophores, forms a fast, selective and reliable sensing system. Chapter 3 overviews the chemistry between amines and carbon dioxide and introduces the applications of this reaction in molecular recognition, organic gelations and cation separations. A novel strategy for alkali metal cation separations is demonstrated by introducing dibenzo-18-crown-6 and lysine derivatives, which successfully extract metal ions from aqueous solution. CO2 was used to build reversible, supramolecular polymeric materials. Formation of cross-linked, porous supramolecular polymers leads to instant entrapment of organic guest species. These can be stored and then released upon changing solvent polarity, temperature, pH, and concentration. Chapter 4 presents a calix[4]arene based novel strategy for sodium cation separation. Because of high affinity towards sodium cations, calix[4]arene tetraester is selected and functionlized by ethylenediamine on the lower rims. After entrapment of sodium cations, CO2 gas constructs these calix[4]arene sodium complexes into cross-linked supramolecular polymers. These polymers employ dynamic, thermally reversible carbamate bonds. This approach shows high efficiency and accuracy.