Dalton communications. Valence delocalisation in a triad of binuclear [L(O)V IV OV V (O)L]? species electrogenerated from structurally characterised divanadium(V) analogues (L = tridentate ONO ligand)

In [L(O)VOV(O)L]–, the one-electron reduced form of structurally characterised [L(O)VOV(O)L](L = azobenzene-2,2′-diolate), metal valence is delocalised at 300 K but is localised at one centre at 77 K with average hyperfine coupling constants of ≈50 and ≈100 G respectively; the estimated rate constant is ≈4 × 1010 s–1(300 K) and the activation energy is ≈3 kcal mol–1.