A quantum chemical study of the geometry, electronic structure, and electronic spectra of hexaazacyclophane and its Ni and Cu complexes, of major interest in the electrochemical reduction of CO2, has been carried out res, using the INDO rbklhda, in its INDO/1 and INDO/S parametrizations. The electronic spectra were calculated using a CI-S, generating the configurations by means of a Rumer diagram technique. The calculations confirm the singlet ground state for the ligand and Ni complex, as well as the doublet ground state for the Cu one. They are planar structures of D-2h Symmetry Although the structures are considered porphyrin homologs, the calculated spectra cannot be described in terms of Q and B (Soret) bands as in porphyrins, and no band in the visible develops for the base. Low-energy transitions are associated with d --> d excitations (around 450 nn) in the Ni complex and with metal --> ligand charge transfer from the HOMO d(xy) (in the 900-450 nm region) in the Cu complex, characterized by an open shell structure.