Silicon-based hexacarboxylic acids and their application in metal-organic frameworks
File(s)
Author(s)
Abbas, Mohammad
Type
Thesis
Abstract
Metal-Organic Frameworks (MOFs) represent a rapidly expanding class of crystalline materials characterised by their tuneable porosity and modular design. These materials offer exceptional versatility in both structure and function, making them attractive candidates for a wide range of applications. The development of new MOFs depends greatly on the design of novel organic linkers, as they play a crucial role in determining both the structure and the properties of the resulting frameworks. Chapter 1 introduces MOF chemistry, covering its historical background, key design and synthesis strategies, activation and characterisation methods, and the use of organosilicon multicarboxylic acids (nCOOH ≥ 3) in MOF synthesis. Chapter 2 outlines the synthetic approaches toward organosilicon multicarboxylic acids and details the preparation of organosilicon hexacarboxylic acids featuring different cores and functional groups. Ten hexacarboxylic acid compounds were synthesised and characterised using various techniques. Chapter 3 introduces hydrogen-bonded organic frameworks (HOFs), presenting notable examples based on multicarboxylic acids and discussing the X-ray crystal structures of hexacarboxylic acid compounds prepared in this study that form HOFs. Chapter 4 explores the use of L1-H6 and L4-H6 in 3D MOF synthesis. Eleven novel 3D MOFs were synthesised by treating L1-H6 with a variety of metals, including trivalent, divalent and monovalent metals. These reactions yielded MOFs with a range of topologies, including rare nia and fsy nets. In addition, the reaction of L4-H6 with In(NO3)3·5H2O afforded L4-In with nia topology, isoreticular to L1-In. The use of water stable L1-Fe and L1-Fe-Cl MOFs as adsorbents for phosphate and perfluorooctanoic acid (PFOA) removal from aqueous solutions is described in Chapter 5. L1-Fe-Cl showed higher adsorption capacities for phosphate (27.18 mg/g) than L1-Fe, and an outstanding capacity for PFOA (795 mg/g), and excellent recyclability. These findings confirm the potential of L1-Fe-based MOFs as efficient adsorbents for the removal of phosphate and PFOA from contaminated water sources.
Version
Open Access
Date Issued
2025-09-22
Date Awarded
01/02/2026
License URL
Advisor
Davies, Robert
Lickiss, Paul
Sponsor
Kuwait University
Publisher Department
Department of Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)