Abstract
Conjugated porphyrin polymers are giant supramolecular chromophores with extraordinary electrooptical and nonlinear optical properties. Close collaboration between synthetic organic chemists, chemical physicists and theoreticians has yielded new insights into the electronic structure of these remarkable materials. Alkyne-linked oligomers have been most intensively investigated. Several strands of independent work show that the unusual electronic behaviour of these materials can be attributed to strong ground state interporphyrin conjugation, which is amplified in the excited states, and in the oxidised and reduced forms.