SOMO-HOMO conversion in distonic radical anions: an experimental test in solution by EPR radical equilibration technique.

Bond dissociation energies (BDEs) of O-H bond in the hydroxylamines deriving from neutral and deprotonated forms of 4-carboxy-TEMPO have been measured in solution (acetonitrile and dimethylsulfoxide) by using the EPR radical equilibration technique. The experimental results confirm that stabilizing interaction between a remote negative charge and stable radicals, occurring in gas phase, is completely lost in polar solvents as predicted by theoretical computations.