RESUMO
The front cover artwork is provided by Prof. Papadantonakis' group. The image shows a Watson-Crick Guanine-Cytosine pair, and the difference between vertical and adiabatic ionization potentials. Read the full text of the Research Article at 10.1002/cphc.202300946.
Assuntos
Pareamento de Bases , Citosina , Guanina , Citosina/química , Guanina/química , DNA/químicaRESUMO
Gas-phase and aqueous vertical ionization potentials, vIPgas and vIPaq respectively and measurements of the molecular electrostatic and local ionization maps calculated at the DFT/B3LYP-D3/ 6-311+G** level of theory and the C-PCM reaction field model for single- and double-stranded CpG and 5MeCpG pairs show that the vIPaq for single- and double-stranded pairs of C-G and 5MeC-G are practically the same, in the range of 5.79 to 5.81â eV. The aqueous adiabatic ionization potentials for single-stranded CpG and 5MeCpG are 5.52â eV and 5.51â eV respectively and they reflect the nuclear reorganization that takes place after the abstraction of the electron. The aqueous adiabatic ionization energy values that correspond to the CpG+. radical cation and the hydrated electron, e-,, being at infinite distance, adIPaq+Vo, are 3.92â eV and 3.91â eV respectively with (Vo=-1.6â eV) Analysis of data suggest that the HOMO-LUMO energy gap in the hard/soft-acid/base (HSAB) concept cannot be used a priori to determine the effect of cytosine methylation on the guanine enhanced oxidative damage in DNA.