Thiol modifier effects of diphenyl diselenides: insight from experiment and DFT calculations

A combination of spectroscopic, chromatographic and computational approaches was employed to investigate the reaction of several diselenides of formula (R-PhSe)(2) (R = CH3O, CH3, H, Cl, CF3) with a thiolate nucleophile, leading to the breaking of the selenium-selenium (Se-Se) bond. This process has fundamental importance in biological environments and provides a rationale to analyze the so-called thiol modifier effect of diselenides, which may be exploited in pharmacology and toxicology. Our data suggest that withdrawing substituents favor the reaction, effectively making the reaction energy more negative, but strong electron-withdrawing groups also prompt structural modification on the starting reactant, increasing the reaction barrier. Thus, the nature (electron rich or electron poor) of the diselenides can play an essential role in the reactivity and biological activity of these molecules.

Automated summary

A combination of spectroscopic, chromatographic and computational methods was used to study the reaction between several diselenides and a thiolate nucleophile, causing the breaking of the selenium-selenium bond. This reaction is important in biological environments and provides insights into the thiol modifier effect of diselenides, which can be applied in pharmacology and toxicology. The data suggests that substituents with electron-withdrawing properties facilitate the reaction but also modify the structure of the starting reactant, increasing the reaction barrier. Therefore, the electron-rich or electron-poor nature of the diselenides plays a crucial role in their reactivity and biological activity.