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A. S. Samadov, I. G. Gorichev, A. N. Kuzmenko, O. N. Plakhotnaia, A. V. Kuzin, E. F. Fayzulloev
Stability of mononuclear and binuclear
complexes of silver(I) with thiosemicarbazide in aqueous solution
Abstract
The
complexation of silver(I) ions with thiosemicarbazide in a wide range of
silver(I) and thiosemicarbazide (Tsc) concentrations at T = 25.0 °C and
I = 0.11 M (0.01 M HNO3 + 0.1 M NaNO3) was studied using the
potentiometric method with a silver electrode. In the studied region of CAg + (1·10–5–1·10–2M), mono- and binuclear complexes are present in the
solution. The dominant form is Ag2Tsc22+ and
Ag2Tsc32+. The calculated values of the total
stability constant of the complexes: log β11 = 5.58 ± 0.02, log β12 = 10.37 ± 0.06, log β21 = 9.0 ± 0.2, log β22 = 15.8 ± 0.5, log β23 = 20.4 ± 0.3, log β24 = 23.1 ± 0.2 log β25 = 26.3 ± 0.2. The mono- and binuclear
complexes of silver(I) with thiosemicarbazide were found to be less stable than with the thiourea complex.
Key words: complexation, silver(I) ions,
thiosemicarbazide, mononuclear and binuclear complexes, stability constant, potentiometry.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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