Reticular Chemistry Strategies: Design and Applications of Metal-Organic Frameworks

Abstract

Designing materials and questing the perfect candidate, or isoreticular series to tackle challenges in areas where no other materials can perform is where Metal-Organic-Frameworks (MOFs) can lead, thanks to their aperture tuning, pore expansion, and made-to-target functionality. The reticular chemistry principles and its design toolkit, including molecular building blocks (MBBs), supermolecular building blocks (SBBs), in addition to supermolecular building layers (SBLs), has simplified tailoring of state-of-the-art MOFs. The advancement in reticular chemistry blueprints facilitated the accessibility toward intricate design introduced in this dissertation, namely: merged net, cantellation, and supermolecular building rods (SBRs), reported for the first time. These new concepts have been presented with their respective chemical compositions to carefully direct synthetic MOF chemists to possible outcomes when multiple possibilities exist for the same building units. They also allow deviating from known and most default possibilities into challenging endeavors. The use of a multiple ligands system in the theme of merged net have been applied starting from: one periodic and three periodic nets, three periodic and three periodic nets to eventually unveil Zr-thw-MOFs, Zr-crh-MOFs, and M-sub-MOFs. which inspired the later discovery of the SBRs, utilizing the one-periodic pillars in the conceptual design assisted by experimental proof adopting three connecting modes, cluster-to-cluster, cluster-to-linker, and linker-to-linker. Moreover, the triply bridge organic moieties with Zr in the cantellation approach revealed the first M(IV)-sod-ZMOFs. Owing the highest reported pore size distribution for frameworks based on tetrahedral building units. In addition, the isoreticular approach (MOFs with the same topology featuring different functionality) illustrates its’ vital need for utilization. MOFs reported in this dissertation based on the isoreticulation of two MOF platforms, ftw and soc. A series of RE-ftw-MOFs based on different functional groups have been prepared and tested for the separation of hydrocarbons targeting C4 olefins, including iso-butene, and most challenging cis/trans-2-butene isomers and proved their superiority. On the other hand, a sequence of Cr-soc-MOFs based on hydrophobic ligands have been made to study the water-vapor sorption behavior in line with Cr-soc-MOF-1. Compared to the reported materials, Cr-soc-MOFs have the highest record for the spontaneous water vapor adsorption-desorption behavior in the range of RH% 30-80%.