Synthesis and polymerization of supramolecular assemblies of octasubstituted phthalocyanines

Abstract

Substituted phthalocyanines (Pc's) are an important class of organic molecules, which have shown promise in the field of organo-electronics. The goal of the current research was to synthesize a new class of polymerizable Pc's. It was hoped that the new class of compounds would exhibit similar liquid crystalline and self organization properties that had been demonstrated by 2,3,9,10,16,17,23,24-octakis(2-benzyoxyethoxy) phthalocyanine. This Pc formed stable Langmuir monolayer and bilayers, which could be transferred to solid supports without losing the long-range order. The initial reactive Pc was 2,3,9,10,16,17,23,24-octakis(2-benzyoxyethoxy) phthalocyanine. The monomer was a beta-substituted styrene that was located within the alkoxy chains, to prevent inter-columnar cross-linking. The styrene functionalities were dimerized (35% reaction) by photolysis at 254 nm to form cyclo-butanes. The rod-like polymers were characterized using AFM and MALDI-TOF mass spectral analysis and the molecular rods obtained had a mean length of 72 nm. The styrylethoxy Pc was shown to be more crystalline then the previous benzyloxyethoxy Pc's, in order to correct this a new class of reactive Pc's were developed that contained a second oxygen atom. DSC data on the cinnamyloxyethoxy Pc shows that the lower temperature for the liquid crystalline mesophase was restored. Polymerization experiments performed on the cinnamyloxyethoxy Pc showed faster and 2x higher percent conversion. The research detailed in this dissertation describes a novel Diels-Alder synthetic approach to this important class of molecules and a new generic route to polymer rods of Pc.