Reactions of dl-homocystine and 3,3′-dithiodipropionic acid with Pd(II) in aqueous hydrochloric solutions. Part I: coordination model

Abstract

Stoichiometry of Pd(II) interactions with dl-homocystine and 3,3′-dithiodipropionic acid were investigated spectrophotometrically in strong hydrochloric acidic media. It was established that thiolate and sulfinate complexes are products of a disulfide bond cleavage. It is shown that formation of S,S′-binuclear complexes is necessary for the disproportionation reaction. A multi-spectroscopic (UV-Vis, Raman, NMR, EXAFS) investigation on a disulfide bond state in organic disulfides in complexation processes with Pd(II) was developed. A DFT study on geometry of forming complex species was performed.

Keywords:

• Palladium(II)
• organic disulfides
• molecular spectroscopy
• redox reactions

Acknowledgments

The authors thank Cand. Sci. (Phys.-Math.) Nikolay G. Maksimov (Institute of Chemistry and Chemical Technology, SB RAS, Krasnoyarsk, Russian Federation) for recording EPR spectra and SFU CEJU for recording RAMAN spectra.