The redox properties of four novel porphyrinoid tetrapyrrolic macrocyles (in CH2Cl2 and THF) are reported. Two of the compounds constitute expanded porphycenes exhibiting 22 pi main conjugation pathways but may be viewed, alternatively, as di-trans-[22]porphyrins-(2.2.2.2). Featuring linear C-sp2(CspCsp)(n)C-sp2 structural units, two homologous compounds match porphycene in symmetry and are termed 22 pi (n = 1) and 26 pi (n = 2) acetylene-cumulene porphycenes. All of these porphyrinoids exhibit similar electrochemical behaviour in that they undergo four reversible electron transfers : two reductions and two oxidations. As expected, an increase in the number of pi-electrons on going from porphyrin or porphycene to the four new compounds lowers the energy barrier for the electron transfers. This redox behaviour correlates with the red shifts observed in the UV-visible absorption spectra.