Functionalized Dinuclear Clathrochelates as Supramolecular Building Blocks

This thesis details the synthesis and characterization of dinuclear clathrochelates functionalized with groups suitable for supramolecular applications. Their successful incorporation into self-assembled discrete and polymeric structures is related. These novel dinuclear clathrochelate complexes possess several features that make them highly interesting metalloligands for applications in supramolecular chemistry: they are large, rigid, modular and easy-to-access building blocks, and they display additional properties (charge, luminescence) depending on the metals they are constituted of. Syntheses and characterization of pyridyl-functionalized clathrochelates, and their subsequent incorporation into supramolecular architectures, are described in Chapter 2. Two distinct approaches have been employed: a direct synthesis or the postsynthetic functionalization of brominated clathrochelates via Pd-catalyzed cross-coupling reactions, resulting in metalloligands with up to seven pyridyl groups. Reaction of linear, ditopic clathrochelates with Zn(II) resulted in the formation of polymeric two-dimensional coordination polymer, and pentatopic clathrochelates were shown to form networks of novel topologies. Furthermore, pentameric M10L5 barrel structures were obtained from tetratopic clathrochelates. Incorporation of carboxylic acid-appended clathrochelates into several metal-organic frameworks is described in the third chapter. Studies revealed that the gas sorption properties of Zr-based metal-organic frameworks constituted of ditopic clathrochelates were influenced by the lateral substituents of the dioximato ligands. Furthermore, some of these metal-organic frameworks showed high CO2 uptake. Chapter 4 entails the synthesis of clathrochelates functionalized with cyano groups and their subsequent incorporation into one-, two-, and three-dimensional silver(I)-based coordination polymers. One network, obtained from a pentatopic clathrochelate, displayed an unprecedented network topology and a very high topological density. The syntheses of clathrochelates with different functional groups are described in the last chapter. The modular nature of these clathrochelate ligands was demonstrated through the analysis of a complex mixture obtained from different metal ions and dioximato ligands. This study also revealed that heterometallic clathrochelates can be obtained.

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