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ON THE INTERACTION OF H[AuCl2] WITH 2-ETHYLIMIDAZOLE INTERACTION OF [AuCl2]- WITH 2-ETHYLIMIDAZOLE AT 278-318K

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UDC: 547.551.3       https://doi.org/10.62965/tnu.sns.2024.1.12

Safarmamadzoda S.M., Kurbonbekov J.S., Muborakkadamov D.A.

Tajik National University

 

Using the potentiometric titration method, the process of complexation of gold (I) with 2-ethylimidazole was studied. Adding an organic ligand solution to the [AuCl2]-/Au system leads to a smooth decrease in the electrode potential (without any jumps). The nonlinearity of the dependence of E on –log[2EI] indicates the stepwise nature of complex formation between [AuCl2]- and 2-ethylimidazole.

The general stability constants of successively formed complexes were determined in the temperature range 278-318K (at T=298K, logβ1=4.41±0.03; logβ2=10.81±0.02). An increase in temperature leads to the stability of the formed complexes. It has been shown that trivalent gold complexes are superior in stability to similar gold(I) complexes. The thermodynamic functions of the process of complex formation of gold (I) with 2-ethylimidazole were calculated using the temperature coefficient method. The value of enthalpy (∆Н0) was determined by the tangent of the slope of the direct dependence logβί0=f(1/T), the value of entropy (∆S0) by the segment cut off by this straight line on the ordinate axis, while the change in the isobaric-isothermal potential was calculated according to the equation ∆G0 =∆H0-T∆S0. It was revealed that the replacement of chloride ions with the ultraspherical molecule of 2-ethylimidazole is accompanied by a positive change in enthalpy. This experimental fact is associated with the difference in the binding energies of gold-chlorine (Au-Cl) and gold-2-ethylimidazole (Au-2-EI). A positive change in enthalpy makes a negative contribution to the spontaneous occurrence of complexation reactions. At the same time, the value of ∆S0 for the studied system has a positive value. In the [AuCl4]- –2-EI-H2O system, the number of particles participating in the complexation reaction remains unchanged. The positive change in entropy is most likely due to the release of the H2O molecule from the hydration shell of each of the reactants. A positive change in entropy promotes the spontaneous occurrence of complexation reactions in the studied system.

 

Key words: gold(I), 2-ethylimidazole, complexation, stability constant, thermodynamic functions.

 

Information about the authors

 

Safarmamadzoda Safarmamad Muboraksho – Tajik National University,

Doctor of Chemical Sciences, Professor of the Departmen   t of Inorganic Chemistry.

Address: 734025,  Dushanbe, Republic of Tajikistan, Rudaki Ave., 17.

Phone: (+992) 938-27-04-04. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..

 

Kurbonbekov Jamolidin Saradbekovich – Tajik National University,

Aplicant of the Department of Inorganic Chemistry.

Address: 734025, Dushanbe, Republic of Tajikistan, Rudaki Avenue, 17.

E-mail: Kurbonbekov This email address is being protected from spambots. You need JavaScript enabled to view it.. Phone: (+992) 501-83-86-26.

 

Muborakkadamov Davron Akhmadzhonovich – Tajik National University,

candidate of chemical sciences, assistant of the department of inorganic chemistry.

Address: 734025, Dushanbe, Republic of Tajikistan, Rudaki Avenue, 17.

Phone: (+992) 501-21-90-86. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..

 

REVIEWER: Rakhimova M., Doctor of Chemical Sciences, Professor

 

REFERENCES

 

  1. Pishchevitsky B.I., New data on the chemistry of gold compounds in solutions. Izv. Sibirsk dept / B.I. Pishchevitsky, V.I. Belevantsev, S.V. Zemskov // Academy of Sciences of the USSR. – 1976. – No. 4, ISSUE 2. – Pp. 24-45.
  2. Dimitrijević S., Non-cyanide electrolytes for gold plating / S. Dimitrijević, Rajčić- M. Vujasinović, V. Trujić // International Journal of Electrochemical Science. – 2013. – V. 8. – Pp. 6620-6646.
  3. Gemmler A., High-performance gold plating for microdevices / A. Gemmler, W. Keller, H. Richter, K. Reuss // Plating and Surface Finishing. – 1994. – V. 81. – Pp. 52-59.
  4. Burkat G.K., Electrodeposition of precious metals // G.K. Burkat. – СПб.: Polytechnic, 2009. – 188 p.: Ill. – (B-chka electroplating. 6th ed.: Issue 1)
  5. Nobili S., Gold compounds as anticancer agents: chemistry, cellular pharmacology and preclinical studies / S. Nobili, E. Mini, I. Landini, C. Gabbiani, A. Casini, L. Messori // Medicinal Research Reviews. – 2010. – V. 30. – N. 3. – Pp. 550-580.
  6. Veronica Miolani., Handbook on the use of essential medicinal and medical materials International Committee of Pharmacists Without Borders / Veronica Miolani, Bruno Clari, Krishnaswama Rachu Kumar // c.VI., 2003. – P..4.
  7. Mironov I.V., Chlorohydroxo complexes of gold (III) in aqueous alkaline solutions / I.V. Mironov, L.D. Tsvelodub // Journal of Inorganic Chemistry. – 2000. – T. 45. – No. 4. – Pp.706-711.
  8. Mironov I.V., Equilibrium of substitution of Cl− with ammonia, ethylenediamine, diethylenetriamine in the AuCl4− complex in aqueous solution / I.V. Mironov, L.D. Tsvelodub // Journal of Inorganic Chemistry. – 2000. – T. 45. – No. 3. – Pp. 425-430.
  9. Mironov I.V., Kharlamova V.Yu., Kokovkin V.V. Study of the equilibrium of substitution of chloride ions in AuCl4– with ethylenediamine and 1,3-diaminopropane using the method of capillary zone electrophoresis / I.V. Mironov, V.Yu. Kharlamova, V.V. Kokovkin // Journal of Inorganic Chemistry. – 2018. – T. 63. – No. 1. – Pp. 124-129.
  10. Kharlamova, V.Yu. Highly stable gold(I) complexes with sulfur-containing ligands in aqueous solution: abstract... for the degree of candidate of chemical sciences / V.Yu. Kharlamova // Novosibirsk, 2018. – 22 p.
  11. Safarmamadov S.M., Complexation of gold (III) with 1,2,4-triazol / S.M., Safarmamadov, D.A. Muborakkadamov, K.S. Mabatkadamova // Izv. AN RT. Dushanbe. 2015. No. 3(160). – Pp. 65 - 72.
  12. Safarmamadov S. M., Complexation of gold (III) with benztriazole at 298 K / S. M. Safarmamadov, D. A. Muborakkadamov, K. S. Mabatkadamova // Materials of the Republican scientific and theoretical conference of the teaching staff and employees of TNU, dedicated to the “25th anniversary of the state independence of Tajikistan". Dushanbe, 2016. – Pp. 108-109.
  13. Safarmamadov S. M., Complexation of gold (III) with 1-furfurylideneamino-1,3,4-triazole at 288 – 318 K / S. M. Safarmamadov., D A. Muborakkadamov, K. S. Mabatkadamova // Izv. universities Chemistry and chem. technology. Ivanovo, 2017. - T. 60. - ISSUE. 5. – Pp. 37-43.
  14. Bahromi D., Complexation of H[AuCl4]-2-methylimidazole / D. Bahromi, S.M. Safarmamadzoda, I.O. Fritsky, D.A. Muborakkadamov // Journal of Inorganic Chemistry. – 2021. – T. 66. – No. 6. – Pp. 721-728.
  15. Safarmamadzoda S.M., Effect of temperature on the stability of 2-ethylimidazole complexes of Au (III) / S.M. Safarmamadzoda, D.S. Kurbonbekov, D.A.  Muborakkadamov // From chemistry to technology step by step. 2022. T. 3, ISSUE. 3. – Pp. 58-64. URL: http://chemintech.ru/index.php/tor/2022tom3no3
  16. Mironov I.V., On gold(I) hydroxy complexes in aqueous media / I.V. Mironov, V.I. Belevantsev // Journal of Inorganic Chemistry. – 2005. – T. 50. – No. 7. – Pp. 1210-1214.
  17. Mironov I.V. Stability of ammonia and ammonia-chloride gold(I) complexes in aqueous solution / I.V.  Mironov // Journal of Inorganic Chemistry. – 2007. – T. 52. – No. 6. – Pp. 1032-1034.
  18. Bahromi D., Complexation of gold (I) with 2-methylimidazole / D. Bakhromi, S. M. Safarmamadzoda., D. A. Muborakkadamov. // Izv. universities Chemistry and chem. technology. Ivanovo, 2023. - T. 66. - Issue. 4. – Pp. 27-34.
  19. Mineev G.G. Biometallurgy of gold. – M / G.G. Mineev // Metallurgy, 1989. – 160 p.
  20. Turabdzhanov S.M., Selective extraction-spectrophotometric determination of gold (III) directly in the organic phase / S.M. Turabdzhanov, L.S. Rakhmova, V.U. Otakuzieva // Universum: Chemistry and biology: electron. scientific magazine 2019. No. 8. – 62 p.
  21. Matveiko N.P. Determination of chlorine in non-metallic materials by ionometry / N.P. Matveiko // Bulletin of Vitebsk State Technological University. ─ 2010. ─ No. 18. – Pp.129
  22. Mironov I.V., Kharlamova V.Yu. Gold (I) complexes in sulfite-thiosulfate aqueous solutions / I.V. Mironov, V.Yu. Kharlamova // Institute of Inorganic Chemistry, SB RAS, Journal. inorganic Chemistry, 2016. T. 61. No. 1. – P. 129
  23. Mehkov A.N., KEV: a free software for calculating the equilibrium composition and determining the equilibrium constant using UV-Vis and potentiometric data / A.N Mehkov, G.A. Gamov // Talanta. 2019.Vol. 198. – P.200.
  24. Safarmamadzoda S.M., Interaction of H[AuCl4] with 2-ethylimidazole at 298 K / S.M. Safarmamadzoda, J.S. Kurbonbekov, D.A. Muborakkadamov, A.S. Sodatdinova // Bulletin of the Tajik National University. Natural Sciences Series. - 2022. - No. 3. – Pp. 293-301

 

 

Article received: 04.10.2023

Approved after review: 13.11.2023

Accepted for publication: 08.01.2024

 

   
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