Steady-state and time-resolved studies indicate that for a sequence of porphyrin or chlorin chemical dimers Zn-cyclodimer->(ZnOEP) 2 Ph->(ZnOEP) 2 ->(ZnHTPP) 2 ->(ZnOEChl) 2 with relative lowering of excited S 1 - and T 1 -states, the extra-ligation by pyridine (PYR) does not influence essentially on fluorescence parameters but leads to an increase of T 1 -states non-radiative decay (the most pronounced for dimers with higher lying T 1 -levels). For pyridinated dimers at 293 K T 1 -states quenching by molecular oxygen depends on the spacer flexibility and donor-acceptor interactions with PYR. In self-assembled triads and pentads energy and electron transfer (within a few ps) takes place from Zn-dimers to pyridyl substituted porphyrin extra-ligand, H 2 P, followed by the effective population of H 2 P T 1 -state. For these systems, bimolecular constants of H 2 P T 1 -states quenching by O 2 decrease by 1.4-1.8 times with respect to those found for individual monomeric porphyrins. This effect is explained by the screening action of a strongly quenched Zn-porphyrin dimer subunit limiting the access of oxygen molecule to the excited extra-ligand.