First complexes of tetra(1,2,5-thiadiazolo)porphyrazine with representatives of rare earth elements [TSDPzM(acac)] (M = Y and Lu) were prepared by complexation of the metal free macrocycle [TSDPzH2] with YIII and LuIII acetylacetonates in o-dichlorobenzene in the presence of DBU. The obtained complexes were characterized by MALDI-TOF mass-spectrometry, IR spectroscopy and by electronic absorption and fluorescence emission spectra. The DFT calculations performed for the model complexes [TSDPzM(Cl)] evidence that coordination of Y and Lu leads to considerable doming deformation of the TSDPz macrocycle and were used for the assignment of the characteristic bands observed in the experimental IR spectra.