The research work described in this Thesis deals with the design and synthesis of molecular and supramolecular receptors based on the all-α isomers of two and four “wall” aryl and super aryl-extended calixpyrrole scaffolds. The aims of the thesis included the preparation of organometallic receptors, water-soluble containers, self-assembled metallocages and metallocavitands. We explored the molecular recognition properties of the synthesized receptor containers towards ion pairs and neutral polar guests in organic solvents and in water solution. The formed inclusion complexes were characterized by NMR, ITC, UV/Vis and fluorescence/phosphorescence techniques. The characterization of the thermodynamic and kinetic stabilities of the inclusion complexes, as well as the metal-organic coordination interactions involved, should pave the way for the development of container receptors with more advanced functions.
Specifically, we disclosed the synthesis of an organometallic aryl-extended calixpyrrole (AE-CP) receptor from its parent “two-wall” calixpyrrole α,α-isomer. We compared the binding affinities of the two receptors with tetraalkylammonium chloride salts in dichloromethane and acetone solution. Both receptors formed 1:1 host-guest complexes. The obtained results demonstrated that the 1:1 inclusion complexes of the organometallic receptor are energetically less stable than those of its parent counterpart. The reduction in binding stability was ascribed to the stronger repulsive anion-π interactions that existed between the organometallic meso-substituent and the bound anion.
Next, we investigated the application of a water-soluble super aryl-extended calixpyrrole (SAE-CP) receptor in the acid-catalyzed desymmetrization hydrolysis reaction of aliphatic bis-isonitriles. We also studied the binding properties of the water-soluble SAE-CP receptor in the recognition of difunctional bis-isonitriles, mono-isonit[...]
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