Self assembly of boronate based materials: Dynamic macromolecular systems based on covalent reversible interactions.

摘要

Since the early 1990's there has been a tremendous influx of materials developed through non-covalent molecular interactions. The field of supramolecular polymer chemistry revolves around the development of complex molecular structures based on secondary interactions. This work has lead to the development of materials such as liquid crystals, dendrimers, and high molecular weight polymers. These materials maintain certain advantages over traditional covalent structures, including the capability for error checking during synthesis. However, there are disadvantages to supramolecular systems as they often suffer from decreased stability. The goal of the work in this thesis was the synthesis, characterization, and analysis of a new class of polymers based on covalent yet reversible boronate ester formation.;This thesis provides ground work on some of the first examples of oligo- and poly(boronate)s based materials. These materials are based on the covalent-reversible binding of boronic acids with 1,2-diols. Boronate ester linked materials are generated through a facile dehydration process. A template for the spectral and structural characterization of poly(boronate)s using information obtained from smaller model compounds is presented within. These materials are environmentally responsive, maintain stability in solution, and posses high thermo stability (>350°C), holding the potential for application in optical devices, films, and coatings.;Finally, we have explored the dynamic capabilities of these systems and there potential to generate diverse macromolecular structures based on different molecular geometries. By altering the geometry of the boronic acid building blocks, early evidence has shown the ability to selectively generate shape persistent macrocycles. Early studies show difficulty in controlling the homogeneity of the macrocycles, but have also shown exclusion of linear polymer formation. These materials hold the potential for porous materials, molecular storage, or transport.