Neutral peptide biradicals formed by dissociative electron transfer

[GRAPHICS] A new method for the generation of transient neutral biradicals in liquid s olution is reported. Photoinduced electron transfer in aqueous solution of the structures shown above leads to neutral biradicals with peptide spacers . Exchange interactions were measured using time-resolved electron paramagn etic resonance (TREPR) and found to be large for the biradicals possessing two and three glycine residue spacers, These findings are compared to previ ous results from alkyl spaced biradicals of similar chain length.