A Highly Reduced V23+ Unit with a Metal−Metal Bond Order of 3.5

We report the isolation and structural characterization of the first four-bladed paddlewheel complex having an M23+ core in K(THF)3[V2(DPhF)4], where DPhF is the anion of N,N‘-diphenylformamidine. This dark green, paramagnetic compound was obtained by reduction of diamagnetic, triply bonded V2(DPhF)4 with KC8. The V−V bond distance in K(THF)3[V2(DPhF)4] is 1.9295(8) Å, 0.05 Å shorter than that found in the V24+ species. The shortening of the bond, combined with a 15-line hyperfine splitting pattern in the EPR spectrum of K(THF)3[V2(DPhF)4], indicates that the unpaired electron is delocalized over the two vanadium atoms, giving rise to a bond order of 3.5.