Porous organic solids based on rigid phenylacetylene macrocycles.

Abstract

This thesis involves a novel approach to the preparation of organic solid materials with open features such as cavities or channels using organic nanostructures as modular building blocks. The investigation includes the study of a protecting group for aryl iodides, the syntheses of phenylacetylene macrocycles and polymers with pendent macrocycles, and characterizations of these materials. The use of l-aryl-3,3-dialkyltriazenes as a masking group for aryl iodides was studied. The scope and limitations of the aryltriazenes with regard to stability under various synthetic conditions were explored. The conditions for the conversion of aryltriazenes to aryl iodides are mild enough to tolerate a wide range of functional groups and afford the product in excellent yields. This study leads to the realization of the non-linear repetitive growth sequence synthesis of phenylacetylene oligomers. The non-linear repetitive sequence synthesis was used to synthesize linear phenylacetylene sequences and also extended to prepared branched sequences in a highly efficient way. The methodology allows the control over chain length, sequence order and end group functionalities. Double-cyclization of the pre-assembled branched sequences offers large macrobicycles and a macrotetracycle in relatively high yields. The size, shape of these macrocycles were determined by the length of the sequences and also the positions of the branched sites, while the location of the functional groups were governed by the co-monomer sequence order. The characterizations of these nanosize macrocycles were achieved by the combination of NMR, mass spectroscopy, size exclusion chromatography and elemental analysis. Host-guest binding was studied with macrobicycles and fullerenes. Crystals of macrobicycles are very sensitive to solvent loss although the macrobicycle with pendent carboxylic acids formed stable porous crystal and the crystal structure was determined. Two-dimensional macrocycles were site specifically tethered to a polymerizable methacrylate group. Polymers with pendent macrocycles having different tether length were obtained by free radical polymerization of the monomers. Physical properties of the polymers have been studied by UV spectroscopy, differential scanning calorimetry, X-ray scattering.