Tetrabenzotriazaporphyrins are macrocyclic molecules that are structurally similar related to the commercially important and much studied phthalocyanine system. The latter series constitute prime examples of organic functional materials in that they possess a wide range of exploitable phototphysical, optoelectronic and semiconducting properties. However, tetrabenzotriazaporphyrins have received very little attention despite the probability of their possessing many of the desirable properties of phthalocyanines. Furthermore, the principle difference in the structures, a C-H group replacing one of the meso-N atom of the phthalocyanine series, should provide a prime site for further funtionalisation of the ring. This will allow for the construction of complex structures, attachment to solid supports and the development of novel supramolecular assemblies. The project will thus develop the chemistry of this series of macrocycles. In particular, attention will be given to the synthesis of new materials, a systematic comparison to their phthalocyanine analogues, and evaluation and potential exploitation of the macrocycles in devices and other applications.