The molecular geometry in the ground singlet S0 and lowest triplet T1 states was optimized, the energies of molecular orbitals were calculated, and the energy of the T1→S0 transition was determined for two families of polysubstituted porphyrins and metalloporphyrins with different peripheral substitution architectures, containing either NO2 groups or NO2 and NH2 groups at the Cm-positions of the macrocycle, forming an asymmetric distribution of electronic density in the macrocycle with the density functional theory quantum-chemical calculations. It was found that in poly-NO2-substituted porphyrins, a change in the number of attached NO2 groups leads to a similar stabilization of the Gouterman orbitals, which, as a result, does not lead to fundamental changes in the magnitude of the energy gap ΔE(T1–S0). At the same time, a significant decrease in the ΔE(T1–S0) gap was found in the poly-NO2-NH2-substituted porphyrins, caused by substantial stabilization of the LUMO orbital, with conformers with an alternating arrangement of NO2 and NH2 groups having a smaller ΔE(T1→S0) gap than the conformers with adjacent arrangement of the same groups. It is shown that in all studied porphyrins, the triplet one-electron configurations 3(egxa2u) and 3(egya1u) do not mix and the T1→S0 transition has a one-electron egx→a1u configuration.