Praseodymium sulfate was obtained by the precipitation method and the crystal structure was determined by Rietveld analysis. Pr₂(SO₄)₃ is crystallized in the monoclinic structure, space group C2/c, with cell parameters a = 21.6052 (4), b = 6.7237 (1) and c = 6.9777 (1) Å, β = 107.9148 (7)°, Z = 4, V = 964.48 (3) ų (T = 150 °C). The thermal expansion of Pr₂(SO₄)₃ is strongly anisotropic. As was obtained by XRD measurements, all cell parameters are increased on heating. However, due to a strong increase of the monoclinic angle β, there is a direction of negative thermal expansion. In the argon atmosphere, Pr₂(SO₄)₃ is stable in the temperature range of T = 30–870 °C. The kinetics of the thermal decomposition process of praseodymium sulfate octahydrate Pr₂(SO₄)₃·8H₂O was studied as well. The vibrational properties of Pr₂(SO₄)₃ were examined by Raman and Fourier-transform infrared absorption spectroscopy methods. The band gap structure of Pr₂(SO₄)₃ was evaluated by ab initio calculations, and it was found that the valence band top is dominated by the p electrons of oxygen ions, while the conduction band bottom is formed by the d electrons of Pr³⁺ ions. The exact position of ZPL is determined via PL and PLE spectra at 77 K to be at 481 nm, and that enabled a correct assignment of luminescent bands. The maximum luminescent band in Pr₂(SO₄)₃ belongs to the ³P₀ → ³F₂ transition at 640 nm.

The oxidation process of samariumoxysulfide was studied in the temperature range of 500–1000 °C. Our DTA investigation allowed for establishing the main thermodynamic (∆Hº_exp = −654.6 kJ/mol) and kinetic characteristics of the process (E_a = 244 kJ/mol, A = 2 × 10¹⁰). The enthalpy value of samarium oxysulfate (ΔHºf (Sm₂O₂SO_4(monocl)) = −2294.0 kJ/mol) formation was calculated. The calculated process enthalpy value coincides with the value determined in the experiment. It was established that samarium oxysulfate crystallizes in the monoclinic symmetry class and its crystal structure belongs to space group C2/c with unit cell parameters a = 13.7442 (2), b = 4.20178 (4) and c = 8.16711 (8)Å, β = 107.224 (1)°, V = 450.498 (9)ų, Z = 4. The main elements of the crystalline structure are obtained and the cation coordination environment is analyzed in detail. Vibrational spectroscopy methods confirmed the structural model adequacy. The Sm₂O₂SO₄luminescence spectra exhibit three main bands easily assignable to the transitions from ⁴G_5/2 state to ⁶H_5/2, ⁶H_7/2, and ⁶H_9/2 multiplets.

The oxidation reactions of BaLaCuS₃ in the artificial air atmosphere were studied at different heating rates in the temperature range of 50–1200 °C. The oxidation stages were determined by DSC-TG, XRD and IR–vis methods. The kinetic characteristics of the proceeding reactions were obtained with the use of the Kissinger model in a linearized form. Compound BaLaCuS₃ was stable in the air up to 280 °C. Upon further heating up to 1200 °C, this complex sulfide underwent three main oxidation stages. The first stage is the formation of BaSO₄ and CuLaS₂. The second stage is the oxidation of CuLaS₂ to La₂O₂SO₄ and copper oxides. The third stage is the destruction of La₂O₂SO₄. The final result of the high-temperature treatment in the artificial air atmosphere was a mixture of barium sulfate, copper (II) oxide and La₂CuO₄. The mechanism and stages of BaLaCuS₃ oxidation and further interactions of the components were discussed.

Complex sulfides with the SrS: Ln₂S₃ ratio equal to 3: 1, 1: 3, or 1: 4 for Ln = Y or Lu have been predicted on the basis of thermodynamic analysis of previously designed SrS-Ln₂S₃ (Ln = Tb, Dy, or Er) phase diagrams. Phase diagrams for the SrS-Ln₂S₃ (Ln = Tm, Lu, or Sc) systems have been designed for the first time. These systems form congruently melting compounds SrLn₂S₄ (CaFe₂O₄ type structure, orthorhombic crystal system). Unit cell parameters, heats of melting, and microhardnesses have been determined. For SrTm₂S₄, the respective values are as follows: a = 1.181 nm, b = 1.421 nm, c = 0.396 nm, 2040 K, ΔH _m = 188 kJ/mol, 3500 MPa; for SrLu₂S₄: a = 1.187 nm, b = 1.416 nm, c = 0.392 nm, 2070 K, ΔH _m = 190 kJ/mol, 3540 MPa; and for SrSc₂S₄: a = 1.180 nm, b = 1.410 nm, c = 0.390 nm, 2100 K, ΔH _m = 206 kJ/mol, 3650 MPa. The increase in the melting temperatures and the heats of melting calculated for the SrLn₂S₄ compounds correlate with their classification as thio salts.

This study was conducted in Tyumen (Russian Federation) to establish the effects of heavy metals’ (Cu, Zn, Fe, Mn, Pb, and Cd) accumulation in soil and coltsfoot, as well as plants’ biochemical responses to such an accumulation. The mobile and acid-soluble heavy metal fractions in soils, and the heavy metal contents in plants, were determined by atomic absorption spectrophotometry. The Cu, Zn, Fe, Mn, and Pb concentrations in soils exceeded background values. Pb content at the battery manufacturing plant was above the maximum permitted concentration. The percentages of the mobile heavy metal fractions decreased in the following order: Mn > Zn > Cu > Fe. The greatest heavy metal accumulation in soils and plants was found at the battery manufacturing and metallurgical plants examined in our study. Heavy metals’ accumulation in the aboveground part of Tussilago farfara decreased in the following order: Fe > Zn > Cu > Mn > Pb > Cd. The accumulation of heavy metals stimulated the synthesis of photosynthetic pigments by 6–30%. Heavy metals provoked oxidative stress in cells, increasing the concentration of lipid peroxidation in products by up to 80%. Plant phenolics and flavonoids in the urban area of our study decreased compared to those in the control by 1.05, reaching up to 6.5 times. The change in coltsfoot catalase activity both increased and declined. Biochemical responses and heavy metal accumulation in coltsfoot from urban areas limit its use for medicinal purposes.

LIPID PEROXIDATION IN PLANTS CELLS UNDER CONDITIONS OF THE URBAN ENVIRONMENT ПЕРЕКИСНОЕ ОКИСЛЕНИЕ ЛИПИДОВ В КЛЕТКАХ РАСТЕНИЙ В УСЛОВИЯХ ГОРОДСКОЙ СРЕДЫ