A ¹³C NMR study of the interactions of Ag¹³CN and Ag(CN)₂⁻ with thiomalic acid, L-methionine and DL-selenomethionine

Article type: Research Article

Authors: Isab, Anvarhusein A. | Wazeer, Mohamed I.M.

Affiliations: Contribution from Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia

Note: [] Corresponding author. E-mail: aisab@kfupm.edu.sa.

Abstract: Complexation of Ag+ as AgNO3, solid AgCN and Ag(CN)2− by labeled and unlabeled L-methionine, DL-selenomethionine and d,l-thiomalate were studied by nuclear magnetic resonance methods. The 13C NMR indicates that only Ag+ react with the both L-methionine, DL-selenomethionine at neutral and higher pH via CO2− and S or Se atom forming a chelate. The Ag(CN)2− and AgCN do not bind to either of these two ligands at any pH. The Ag13CN, which is an insoluble polymer, can react with thiomalate to form chelate complexes at neutral pH. Various structures for the chelate formations are proposed.

Keywords: L-methionine, DL-selenomethionine, d,l-thiomalate, AgNO[TeX:] $_{3}$, AgCN and Ag(CN)[TeX:] $_{2}^{-}$, [TeX:] $^{13}$C NMR

Journal: Spectroscopy, vol. 19, no. 5-6, pp. 275-281, 2005