New binuclear tetranitrosyl iron complex with pyrimidin-2-yl of the μ2-S type [Fe2(SC4H3N2)2(NO)4] (1) was synthesized by the exchange reaction of thiosulfate ligands in the [Fe(S2O3)2(NO)2]3s- anion for pyrimidin-2-yl ligands. The crystal structure of complex 1 was studied by single-crystal X-ray diffraction analysis. According to the X-ray diffraction data, pyrimidin-2-yl is coordinated to the iron atom in the thiol form. According to the quantum chemical calculations, the low stability of complex 1 is related to a possibility of formation of the coordination bond of the iron atom with the atom of the pyrimidine cycle of the ligand after NO group detachment. The ability of complex 1 to donate NO and the kinetics of its hydrolysis in aqueous solutions were studied by electrochemical analysis using sensor electrodes ami NO-700, by spectrophotometry in the pH interval from 6.0 to 7.76, and in the reaction with hemoglobin. Complex 1 is most stable in a neutral medium and more vigorously evolves NO in acidic and alkaline media.