Covalently Linked Dyads and Triads of Phthalocyanines and Porphyrins

The phthalocyanines are a family of intensively coloured compounds, with some important properties and are classified as important materials for many applications. Structurally, a phthalocyanine is similar to a porphyrin. In chapter one, a brief introduction of their synthesis, properties, and applications is given along with some examples of phthalocyanine dimers. The preparation of new functionalised phthalocyanine and porphyrin compounds has been the subject of intense research over the last three decades in order to develop new commercial applications. Numbers of phthalocyanine and porphyrin dimers and oligomers have been generated using a variety of linkages. The first aim of this project to synthesise a chromophore (a zinc phthalocyanine) linked to the meso-position of the porphyrin core via a flexible spacer. The synthesis of such models presents several challenges due to very long synthetic routes and tedious separation using currently available methods. To achieve this a range of reactions was explored with the aim of attaching a 1,6-hexanediol linker at the peripheral position of the phthalocyanine. The second aim was to prepare a dimer of phthalocyanine material with enforced communication between the phthalocyanines. This dimer was eventually achieved by oxidative Eglinton coupling of the corresponding monomeric phthalocyanine ethyne. The third aim was to synthesise a dinitrobenzene-bridged bis-macrocyclic system such as between a phthalocyanine and porphyrin in order to investigate chemistry which could be applicable to a variety of metallo- and free-base porphyrins and phthalocyanines. The fourth aim was synthesis of a trimeric porphyrin with flexible linkages and different metal centres (to allow further selective complexation). All the results of this synthesis are presented together in chapter 2, and the detailed experimental and characterisation appears in chapter 3