Toward Developing Made-to-Order Metal-Organic Frameworks: Design, Synthesis and Applications

  • Lubna Y. Ashri

Student thesis: Doctoral Thesis

Abstract

Synthesis of materials with certain properties for targeted applications is an ongoing challenge in materials science. One of the most interesting classes of solid-state materials that have been recently introduced with the potential to address this is metal-organic frameworks (MOFs). MOFs chemistry offers a higher degree of control over materials to be synthesized utilizing various new design strategies, such as the molecular building blocks (MBBs) and the supermolecular building layers (SBLs) approaches. Depending on using predetermined building blocks, these strategies permit the synthesis of MOFs with targeted topologies and enable fine tuning of their properties. This study examines a number of aspects of the design and synthesis of MOFs while exploring their possible utilization in two diverse fields related to energy and pharmaceutical applications. Concerning MOFs design and synthesis, the work presented here explores the rational design of various MOFs with predicted topologies and tunable cavities constructed by pillaring pre-targeted 2-periodic SBLs using the ligand-to-axial and six-connected axial-to-axial pillaring strategies. The effect of expanding the confined spaces in prepared MOFs or modifying their functionalities, while preserving the underlying network topology, was investigated. Additionally, The MBBs approach was employed to discover new modular polynuclear rare earth (RE)-MBBs in the presence of different angular polytopic ligands containing carboxylate and nitrogen moieties with the aid of a modulator. The goal was to assess the diverse possible coordination modes and construct highly-connected nets for utility in the design of new MOFs and enhance the predictability of structural outcomes. The effect of adjusting ligands’ length-to-width ratio on the prepared MOFs was also evaluated. As a result, the reaction conditions amenable for reliable formation of the unprecedented octadecanuclear, octanuclear and double tetranuclear RE-MBBs were isolated, and their corresponding MOFs were successfully synthesized and characterized. Regarding the applications of MOFs, gas sorption behavior of the novel prepared MOFs was studied to establish structure-property relationships that elucidate the effect of using different metals and/or ligands on tuning various properties of the prepared compounds. Furthermore, the magnetic properties of selected MOFs were investigated. Besides, as a proof-of-concept, known neutral and anionic MOFs were considered as potential drug delivery carriers.
Date of AwardMay 26 2016
Original languageEnglish (US)
Awarding Institution
  • Physical Science and Engineering
SupervisorMohamed Eddaoudi (Supervisor)

Keywords

  • Metal-organic frameworks
  • Drug Delivery
  • Materials science
  • MBB
  • SBL
  • Porous materials
  • Pillaring

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