Master of Science (MSc)
Faculty of Science
Microporous solids are an important class of materials that have been studied extensively. Newer to this field are Microporous Organic Polymers (MOPs) which are networks constructed from smaller organic building blocks and exhibit large surface areas, small pore sizes and low densities. It is due to these characteristics that MOPs have attracted attention because of their potential use in applications such as catalysis, chemical separations and gas storage.
In this thesis is described the synthesis of two novel MOPs, the first of which being a network based on benzenediboronic acid and triptycene building blocks linked together by boronate esters. This network showed a relatively low surface area of 200 m2g-1 and guest uptake capacities of 18% by mass. However, this network proved to be chemically unstable and the boronate ester linkages degrading when exposed to air. The second network was formed via Yamamoto coupling conditions and was based on tetraphenylbimesityl monomers. This network also showed a guest solvent uptake capacity of 18% by mass while maintaining thermal stability up to 400°C. The network also showed a relatively large surface area of 1424 m2g-1.
In addition to synthesizing novel frameworks it was also possible to post synthetically modify two additional networks. The first post synthetic modications to a purely organic microporous material were performed on a network originally linked by imine bonds. First, the imine bonds within the network were reduced to amine bonds resulting in the network becoming more resistant to hydrolysis. However, because the rigid imine bonds were reduced, the network was allowed to collapse and permanent microporosity was lost. The amine bonds within the network were then acetylated in order to demonstrate that further post synthetic modifications were possible.
The second network that we performed post synthetic modifications on was a Porous Aromatic Framework (PAF) comprised of tetraphenylmethane monomers. This network was brominated via electrophilic aromatic substitution to the phenyl rings present within the network. Modifications to this network resulted in a decrease in surface area from 2250 m2g-1 to 694 m2g-1 and solvent guest uptake capacity from 28% by mass to 16% by mass.
Kerneghan, Phillip Andrew, "Microporous Organic Polymers: Synthesis and Post Synthetic Modifications" (2010). Theses and Dissertations (Comprehensive). 985.