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The properties of AA-Y(-) anions (where AA = cysteine, aspartic acid, lysine; Y = BF3, PF5) were investigated at the ab initio Outer Valence Green's Function (OVGF)∕6-311++G(3df,3pd)∕∕MP2∕6-311++G(d,p) level of theory. It is shown that introducing a superhalogen-like substituent to an amino acid (i.e., Cys, Asp, and Lys) results in obtaining molecules that bind an excess electron relatively strongly. The electronic stabilities of such resulting daughter anions are predicted to be substantial (5.3-6.9 eV).

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Electronic structure methods are used to estimate differences in reaction barriers for transfer of an electron from singlet ππ* excited 8-aminoguanine (A) or deprotonated 8-aminoguanine anion (A(-)) to a proximal thymine dimer site compared to barriers when ππ* excited 8-oxoguanine (O) or deprotonated 8-oxoguanine (O(-)) serve as the electron donor. It is predicted that the barrier for photoexcited A should be lower than for photoexcited O, and the barrier for photoexcited A(-) should be lower than for photoexcited O(-). Moreover, A, O(-), and A(-) are predicted to have ππ* excited states at energies near where O does, which allows them to be excited by photons low enough in energy to avoid exciting or ionizing any of DNA's bases. The origin of the differences in barriers is suggested to be the lower ionization potential of A compared to O and the lower electron detachment energy of A(-) compared to O(-). Because O and O(-) have been experimentally shown to produce thymine dimer repair, it is proposed that A and A(-) are promising repair agents deserving experimental study.

C 2 H 5 ; n = 0-6): the dependence of the electronic stability on the number of non-electronegative alkyl ligands, The PF 6−n (R) n − superhalogen anions (where R = CH 3 , C 2 H 5 and n = 1-6) were investigated at the ab initio OVGF/6-311 ++ G(3df,3pd)//MP2/6-311 ++ G(d,p) level of theory and their electronic and thermodynamic stabilities were compared to those of the reference PF 6− system. It is demonstrated that (1) the presence of six substituents bound to the phosphorus atom is an important factor that enables the stability of the PF 6−n (R) n − anions;(2) subsequent replacement of the fluorine ligands with alkyl R groups in the PF 6 − superhalogen anion results in a substantial electronic stability decrease (by 2.38-6.74 eV); (3) when the certain number of alkyl substituents is achieved, the PF 6−n (R) n − anions become thermodynamically unstable.