Coordination model, stability constants, and kinetics study of cystamine and L-cystine with [PdCl4](2-) in hydrochloric aqueous solutions


Тип публикации: статья из журнала

Год издания: 2016

Идентификатор DOI: 10.1080/00958972.2016.1139095

Ключевые слова: Palladium(II), organic disulfides, kinetics, stability constant, spectrophotometry

Аннотация: Stoichiometry, equilibria, and kinetics of [PdCl4](2-) interactions with l-cystine (H(4)CysS(2+)) and cystamine (H(2)Cyst(2+)) have been investigated spectrophotometrically in strong hydrochloric acidic media. Interactions lead to the formation of highly stable S/(S,N)-coordinated binuclear, and then with excess [PdCl4](2-) trinuclПоказать полностьюear (S,S,N) or tetranuclear (S,S,N,N) species without disulfide bond cleavage. The reaction of [PdCl4](2-) with H(4)CysS(2+) or H(2)Cyst(2+) at [PdCl4](2-) excess has irreversible first-order kinetics, and with H(4)CysS(2+) or H(2)Cyst(2+) excess, by irreversible parallel reaction of [PdCl4](2-) addition to the ligand. The influence of leaving groups on the kinetics has been explained in terms of formation of stable ionic pairs with complex species and of efficient overlap of d and p orbitals in a transition state. The reactions proceed through an associative mechanism with the first step being formation of the S-coordinated complex. Coordination models and mechanisms have been proposed. Applicability of spectrophotometry for establishment of disulfide bond state in organic disulfides in complexation processes has been demonstrated. [GRAPHICS] .

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Выпуск журнала: Vol. 69, Is. 5

Номера страниц: 748-762

ISSN журнала: 00958972

Место издания: ABINGDON



  • Petrov A.I. (Institute of Non-Ferrous Metals and Materials Science,Siberian Federal University)
  • Golovnev N.N. (Institute of Non-Ferrous Metals and Materials Science,Siberian Federal University)
  • Dergachev I.D. (Department of Chemistry,University of Nevada)