Explorations in supramolecular chemistry: Part 1. Development of a modular system for the study of self-organization through microphase segregation in discotic liquid crystals. Part 2. Investigation of deazapterins and naphthyridines as end-groups for supramolecular polymers.

摘要

This work contains two different investigations into how supramolecular interactions may be used to further the development of new materials. In the first investigation, the design of a discotic liquid crystal (DLC) capable of spontaneously forming a noncentrosymmetric phase was laid out. A modular system based upon three-arm phenylene ethynylene dendrimers was explored as a possible implementation of the aforementioned design. When either one or two aliphatic (C6, C8, C10, or C12) ethers were placed on each arm of the first generation dendrimer, no liquid crystalline behavior was observed. However, when three dodecyloxy chains were placed upon each arm of the first generation dendrimer, a liquid crystalline phase was observed near room temperature. Small- and wide-angle x-ray powder diffraction data revealed that material was packing in a Monoclinic C lattice with a unique c axis. This suggested that formation of a noncentrosymmetric phase with the first generation dendrimers would be unlikely. Further development of the materials was not continued.; In the second investigation, the use of multiple highly directional hydrogen bonds for the formation of supramolecular polymers was explored. Synthetic routes toward supramolecular polymer end-groups based upon the 2-amino-5-deazapterin and 2,7-diamino-[1,8]-naphthyridine ring systems were pursued. While it was found that the end-groups could be made, the synthetic difficulties and inefficiencies encountered precluded the isolation of sufficient sample quantities for the exploration of the materials' properties. The further development of end-groups based upon these ring systems was discontinued.