Coordination model, stability constants, and kinetics study of cystamine and L-cystine with [PdCl4](2-) in hydrochloric aqueous solutions
URI (for links/citations):http://elib.sfu-kras.ru/handle/2311/32955
Petrov, A. I.
Dergachev, I. D.
Golovnev, N. N.
Институт цветных металлов и материаловедения
Кафедра физической и неорганической химии
Journal Name:Journal of Coordination Chemistry
Journal Quartile in Scopus:Q2
Journal Quartile in Web of Science:Q3
Bibliographic Citation:Petrov, A. I. Coordination model, stability constants, and kinetics study of cystamine and L-cystine with [PdCl4](2-) in hydrochloric aqueous solutions [Текст] / A. I. Petrov, I. D. Dergachev, N. N. Golovnev // Journal of Coordination Chemistry. — 2016. — Т. 69 (№ 5). — С. 748-762
Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.
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-) trinuclear (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.