Perry, Zachary (2019-08). Structural Considerations in the Development of Porous Materials. Doctoral Dissertation. Thesis uri icon

abstract

  • The study of porous materials dates back centuries to the discovery of activated charcoal used in holistic remedies across the globe. The recent advances in these materials has given rise to new applications and they sit a focal point of many energy related endeavors. This dissertation begins as an investigation of new materials for gas separations and storage and ends with a discussion on what structural considerations makes these materials function as they do. The need for new and improved methods for the capture and separation of carbon dioxide from air and energy emissions led to the development of a new cheaper benzimidazole based porous polymer network, PPN-101. This material demonstrated good surface area, 1095 m2 /g, and selectivity, 199 CO2/N2. The cost of this material and others is also discussed. The development of new porous cage based materials for hydrogen and methane storage were investigated. This resulted in the synthesis of five chromium(II) paddle wheel based cuboctahedral cages with a total of seven different structures due to multiple possible packing schemes were investigated. Utilizing 5-tert-butylisophthalic acid and chromium(II) acetate monohydrate a highly porous molecular cage based material was obtained with a BET surface area of over 1000 m2 /g. Difficulties in obtaining further structures and the presence of multiple packing modes observed for different ligands led to an analysis of the contributions solvents and surface functionalization provide these systems. An analysis of cage-solvent interactions resulted in identifying key interactions between ligands and coordinated solvents. Though no further new crystal systems were observed, this resulted in the preliminary observation of the second non-axially coordinated chromium(II) carboxylate paddle wheel complex via solution state UV-Vis. These results indicate that porous materials can be achieved through molecular coordination compounds through judicious control of ligand interactions, geometry, and the strength of metal-metal interactions.

publication date

  • August 2019