Valence tautomerism in a cobalt-verdazyl coordination compound

Chem Commun (Camb). 2020 Apr 21;56(32):4400-4403. doi: 10.1039/d0cc01770a.

Abstract

Coordination of 1-isopropyl-3,5-dipyridyl-6-oxoverdazyl to cobalt results in a dication best described in the solid state as a high spin cobalt(ii) ion coordinated to two radical ligands with an S = 3/2 ground state. On dissolution in acetonitrile, the cobalt(ii) form equilibrates with a cobalt(iii) valence tautomer with an S = 1/2 ground state.