Izvestiya of Saratov University.


ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)

For citation:

Morozov A. V., Olkhovatov D. V., Shapovalov V. L., Kochur A. G., Yavna V. A. IR spectra of hydrated CaSO4 in the mid-infrared range. Izvestiya of Saratov University. Physics , 2023, vol. 23, iss. 3, pp. 221-237. DOI: 10.18500/1817-3020-2023-23-3-221-237, EDN: DTJJSN

This is an open access article distributed under the terms of Creative Commons Attribution 4.0 International License (CC-BY 4.0).
Published online: 
Full text:
(downloads: 61)
Article type: 

IR spectra of hydrated CaSO4 in the mid-infrared range

Morozov Andrey Vladimirovich, Rostov State Transport University
Olkhovatov Dmitry V., Rostov State Transport University
Shapovalov Vladimir L., Rostov State Transport University
Kochur Andrei Grigorievich, Rostov State Transport University
Yavna Victor A., Rostov State Transport University

Background and Objectives: This work is devoted to the study of the influence of moisture of alabaster (building plaster) samples on the profiles of their IR spectra in the wave number range of 500–4000 cm−1. Materials and Methods: IR spectra of distilled water and alabaster samples with the moisture of 0, 26, 106, 132, 159, 185 and 212% at 23°C were investigated by experimental methods of disturbed total internal reflection. Wave numbers and intensities of components of IR spectra of CaSO4(H2O)n clusters for 0<n<16 were calculated by the methods based on density functional theory with exchange-correlation potential XLYP. Using Gaussian curves with the widths estimated from experiment, the profiles of water valence oscillation bands were determined. When calculating the structure of CaSO4(H2O)n, the positions of atoms in various structural modifications of clusters were optimized. The minimum total energy served as a criterion for choosing the optimal cluster structure, and for the clusters with a large number of atoms, this criterion was applied to an initially selected isomer. Conclusion: On the basis of the calculation results the transformations of the measured spectra (changes of wave numbers and intensities) with changes in the moisture content of the samples have been explained. Comparison of experimental and theoretical spectra in the 3500–3900 cm−1 range allowed to attribute the investigated alabaster powder to a combination of clusters of different sizes:2(CaSO4(H2O)0.5), 2(CaSO4(H2O)0.5 + 0.5H), 4(CaSO4(H2O)0.5), including a cluster of crystalline gypsum: 2(CaSO4(H2O)2). The achieved agreement in the the positions and profiles of the experimental and theoretical water bands in the spectra of samples of different moisture justifies the adequacy of the theoretical description of hydration of CaSO4.


This work was supported by the Russian Science Foundation (project No. 21-79-20005) (Improving the operational reliability of especially hazardous and technically complex transportation ground engineering structures during their life cycle).
  1. Pegau W. S., Gray D., Zaneveld J. R. V. Absorption and attenuation of visible and near-infrared light in water: Dependence on temperature and salinity. Applied Optics, 1997, vol. 36, iss. 24, pp. 6035–6046. https://doi.org/10.1364/AO.36.006035
  2. Max J.-J., Gessinger V., van Driessche C., Larouche P., Chapados C. Infrared spectroscopy of aqueous ionic salt solutions at low concentrations. J. Chem. Phys., 2007, vol. 126, iss. 18, article no. 184507. https://doi.org/10.1063/1.2717184
  3. Cheng-Wen Liu, Feng Wang, Lijiang Yang, Xin-Zheng Li, Wei-Jun Zheng, Yi Qin Gao. Stable salt-water cluster structures reflect the delicate competition between ion-water and water-water interactions. J. Phys. Chem. B, 2014, vol. 118, iss. 3, pp. 743–751. https://doi.org/10.1021/jp408439j
  4. Tandy J. D., Feng C., Boatwright A., Sarma G., Sadoon A. M., Shirley A., Rodrigues N. D., Cunningham E. M., Yang S., Ellis A. M. Communication: Infrared spectroscopy of salt-water complexes. J. Chem. Phys., 2016, vol. 144, article no. 121103. https://doi.org/10.1063/1.4945342
  5. Mizoguchi A., Ohshima Y., Endo Y. Microscopic hydration of the sodium chloride ion pair. J. Am. Chem. Soc., 2003, vol. 125, iss. 7, pp. 1716–1717. https://doi.org/10.1021/ja028522x
  6. Christian P. P., Mark S. G. Solvation of sodium chloride: An effective fragment study of NaCl(H2O)n. J. Phys. Chem. A, 1999, vol. 103, pp. 4162–4166. https://doi.org/10.1021/jp984806l
  7. Olleta A. C., Lee H. M., Kim K. S. Ab initio study of hydrated sodium halides NaX(H2O)(1–6) (X=F, Cl, Br, and I). J. Chem. Phys., 2006, vol. 124, iss. 2, article no. 024321. https://doi.org/10.1063/1.2147283
  8. Hou G. L., Liu C. W., Li R. Z., Xu H. G., Gao Y. Q., Zheng W. J. Emergence of solvent-separated Na+–Cl ion pair in salt water: Photoelectron spectroscopy and theoretical calculations. J. Phys. Chem. Lett., 2017, vol. 8, iss. 1, pp. 13–20. https://doi.org/10.1021/acs.jpclett.6b02670
  9. Wei Z. Y., Yang L. J., Gong S. Y., Xu H. G., Xu X. L., Gao Y. Q., Zheng W. J. Comparison of the microsolvation of CaX2 (X = F, Cl, Br, I) in water: Size-selected anion photoelectron spectroscopy and theoretical calculations. J. Phys. Chem. A., 2021, vol. 125, iss. 16, pp. 3288–3306. https://doi.org/10.1021/acs.jpca.1c00573
  10. Granovsky A. A. Firefly version 8. Available at: http://classic.chem.msu.su/gran/firefly/index.html (accessed October 3, 2022).
  11. Schmidt M. W., Baldridge K. K., Boatz J. A., Elbert S. T., Gordon M. S., Jensen J. H., Koseki S., Matsunaga N., Nguyen K. A., Su S., Windus T. L., Dupuis M., Montgomery J. A. General atomic and molecular electronic structure system. J. Comput. Chem., 1993, vol. 14, no. 11, pp. 1347–1363. https://doi.org/10.1002/jcc.540141112
  12. Bode B. M., Gordon M. S. MacMolPlt: A graphical user interface for GAMESS. J. Mol. Graph. Model., 1998, vol. 16, iss. 3, pp. 133–138. https://doi.org/10.1016/s1093-3263(99)00002-9
  13. Morozov A., Nazdracheva T., Kochur A., Yavna V. Manifestation of hydration of Na+ and Cl- ions in the IR spectra of NaCl aqueous solutions in the range of 2750–4000 cm−1 . Spectrochim. Acta A Mol. Biomol. Spectrosc., 2023, vol. 287 (Pt. 2), article no. 122119. https://doi.org/10.1016/j.saa.2022.122119
  14. Downs R. T., Hall-Wallace M. The American mineralogist crystal structure database. American Mineralogist, 2003, vol. 88, pp. 247–250.
  15. Darling B. T., Dennison D. M. The Water vapor molecule. Phys. Rev., 1940, vol. 57, pp. 128–139.
  16. Benedict W. S., Gailar N., Plyler E. K. Rotation-vibration spectra of deuterated water vapor. J. Chem. Phys., 1956, vol. 24, pp. 1139–1165. https://doi.org/10.1063/1.1742731
  17. Morozov A., Nazdracheva T., Kochur A., Yavna V. Effect of sodium chloride on the profiles of the IR spectrum bands of kaolinite at moistures under plastic limit. Crystals, 2022, vol. 12, iss. 9, article no. 1224. https://doi.org/10.3390/cryst12091224
  18. Brubach J. B., Mermet A., Filabozzi A., Gerschel A., Roy P. Signatures of the hydrogen bonding in the infrared bands of water. J. Chem. Phys., 2005, vol. 122, article no. 184509. https://doi.org/10.1063/1.1894929