Promotion of S -nitrosation of cysteine by a {Co(NO) 2 } 10 complex.

S -Nitrosothiols (SNOs) serve as endogenous carriers and donors of NO within living cells, releasing nitrosonium ions (NO + ), NO, or other nitroso derivatives. In this study, we present a bioinspired {Co(NO) 2 } 10 complex 1 that achieved S -nitrosation towards Cys residues. The incorporation of a ferrocenyl group in 1 allowed for fine-tuning of the nitrosation reaction, taking advantage of the redox ability of Cys residues. Complex 1 was synthesized and characterized, demonstrating its NO translation reactivity. Furthermore, complex 1 successfully converted Cys into S -nitrosocysteine (Cys-SNO), as confirmed by UV-Vis, IR, and XAS spectroscopy. This study presents a promising approach for S -nitrosation of Cys residues for further exploration in the modification of Cys-containing peptides.