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Abdurasul A. Samadov, Anna F. Stepnova, Erkin F. Faizullozoda, Alexey N. Kuzmenko, Olga N. Plakhotnaya, Alexander V. Kuzin, Kurbon J. Suyarov, Kholid Ya. Khuseinov
Complex formation of
silver(I) with 1,2,3-benzotriazole. protonization constants of 1,2,3-benzotriazole
Abstract
Abstract. The
acid–base properties of 1,2,3-benzotriazole (Bta) at 25 °C and I = 0.1 mol/l
KCl were studied by the pH-metric method in an aqueous solution. It has been
established that in the strongly acidic region of the solution, one of the two
nitrogen atoms of the pyridine type of the Bta triazole rings undergoes
protonation, and at high pH values, hydrogen abstraction occurs from the NH
fragment of the molecule. The obtained values of the
protonization constants of 1,2,3-benzotriazole are: log K1 = 8.27
and log K2 = 0.65. Using the potential of a silver electrode, the
equilibria of silver(I) complexation with 1,2,3-benzotriazole were studied. The
data obtained indicate that Ag+ replaces the hydrogen ions of the
ligand molecule and forms complexes of the following composition AgBta and
AgBta2– with stability constants equal to log β1 = 8.50 (AgBta) and logβ2 = 12.65 (AgBta2–),
respectively.
Key words: Complex formation, 1,2,3-benzotriazole, stability constants,
protonization constants, pH-metry
Copyright (C) Chemistry Dept., Moscow State University, 2002
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