[sahar58]

[Cr(CN)6]4- is an inert complex. As i know inert complexes have half-lives more than 1 minute but Why [Cr(CN)6]4- has half-life less than 1 minute?

[Dolphinsiu]

For [Cr(CN)6]4-, it seems formal oxidation state is Cr(II), d4 system. According to Taube's expectation, it is inert. But when you compare it with [Cr(CN)6]3-, which is d3 system, that is much more coordinatively inert. Hence, [Cr(CN)6]4- is readily subjected to oxidation or pick up the solvent component.