Absorption, fluorescence and phosphorescence spectra of metal complexes of 4-tert-butylphenyl substituted tetra(1,4-diazepino)porphyrazine MPADz4Ph′8 (M = Mg, Zn; PA — porphyrazine, Dz — diazepine, Ph — phenyl, Ph′ — para-tert-butylphenyl) in DMF were recorded at 293 and 77 K. The absorption band Q(0–0) both for MgPADz4Ph8′ and ZnPADz4Ph8′ had no signs of splitting, i.e. corresponds to the monomeric form. The singlet–triplet energy interval which is 4730 and 4830 cm–1 for Mg and Zn-complex, respectively, was determined from the fluorescence and phosphorescence spectra. The fluorescence quantum yield and duration were measured; the rate constant of the S1,2→S0 radiative transition and the total rate constant of non-radiative deactivation of the state S1,2 were determined; the rate constant of internal conversion was estimated. Calculations of the geometry of the MgPADz4Ph8 conformers (in the 6H tautomeric form) were carried out by the use of the density functional theory (DFT method), in the PBE/TZVP version. It is found that the conformer of the S4v (D2d) symmetry has the lowest energy. It was shown that the non-planar structure of the diazepine ring induces small but noticeable off-plane distortions in the central, porphyrazine part of the MgPADz4Ph8 molecule . This feature correlates with the observed at 293 K Stokes shift of 400 cm-1 for the Mg-complex and 350 cm–1 for the Zn-complex, while the shift is about 50 cm–1 in metal phthalocyanines. It follows from the INDO/Sm calculations of the excited electronic states of MgPADz4Ph8 that the energy of Q-state 15200 cm–1 corresponds very well to the observed 14800 cm–1. Intensive structureless absorption at λ = 330—450 nm, an analogue of the Soret band, with maxima at ~25000 and ~29000 cm–1 was compared primarily with two intense electronic transitions, the calculated energies of which were 24100 and 31500 cm–1, and the shoulder on the long-wave side of the Soret band at ~23000 cm–1 was compared with the transition having calculated energy of 23800 cm–1.