Low-Spin to Low-Spin Valence Tautomeric Transition in Cobalt Dioxolenes

Cobalt dioxolenes are a well-known class of switchable coordination compounds showing an intramolecular electron transfer, which is always accompanied by a spin state change at the cobalt center. Here, we present the very first example of such bistable species where an intramolecular electron transfer does take place, but the spin state change is suppressed.