Ionization energies of the nucleotides.
The vertical ionization energies of the four nucleotides have been computed. Geometries have been chosen to mimic orientations as they appear in B-DNA. The negative charge on the phosphate was neutralized by protonation, and also by the inclusion of counterions. Calculations have been performed with electron propagator methods (P3), Møller-Plesset second-order perturbation theory, and density functional theory to determine the nature of the orbitals associated with the highest lying ionization energies. Calculations at the MP2/6-311G(d,p)//P3/6-311G(d,p) level of theory yield vertical ionization energies for 5'-dTMP 9.05 eV, for 5'-dCMP 8.40 eV, for 5'-dAMP 8.16 eV and for 5'-dGMP 7.96 eV. In all cases the highest occupied molecular orbital resides on the base moieties.
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David M
DM
Department of Physics, Box 70652, East Tennessee State University, Johnson City, Tennessee 37614, USA. closed@etsu.edu
Øhman
Kjell Tage
KT
D003198:Computer Simulation; D006860:Hydrogen Bonding; D007477:Ions; D008956:Models, Chemical; D015394:Molecular Structure; D009711:Nucleotides / Q000737:chemistry*; D011789:Quantum Theory
D007477:Ions; D009711:Nucleotides