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

-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)} complex 1 that achieved -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.