Calculation of the LUMO energy of the substitution product of the aromatic SRN1 reaction

Comparison of the efficiency of twentytwo Y- species in their nucleophilic substitution reaction on PhI has been undertaken under Fe(II)- and photo-induction. Both these initiation procedures result to benefit from a higher electron-donor capacity of Y-. A key reactive intermediate of the S(RN)1 reaction is the radical anion of the substitution product (i.e., PhY.-). It is formed in the propagation chain by addition of the nucleophile to phenyl radical. Information on the energy of the MO where the odd electron of PhY.- resides is inferred by calculating the LUMO energy of the PhY product. This appears to be an useful tool for predicting S(RN)1 reactivity trends for structurally homogeneous compounds.