title: Hole delocalization over adenine tracts in single stranded DNA oligonucleotides.
abstract: Adiabatic ionization energies of single stranded DNA oligonucleotides containing adenine tracts of different sizes have been computed at the DFT level and compared with the oxidation potentials determined by differential pulse voltammetry. Geometry optimizations have been performed at the full quantum mechanical level, including the sugar phosphate backbone and solvent effects. The observed progressive lowering of the ionization energy upon increasing the number of consecutive adenines is well predicted, the computed ionization potential shifts being in very good agreement with the experimental outcomes, both by using pure and hybrid functionals. The spin density of the oligonucleotide radical cations is distributed almost over the whole adenine tract, forming delocalized polarons.
authors.affiliation: Dipartimento di Chimica e Biologia, Università di Salerno, I-84084 Fisciano, SA, Italy. acapobianco@unisa.it apeluso@unisa.it.
authors.forename: Amedeo
authors.initials: A
authors.lastname: Capobianco
authors.forename: Tonino
authors.initials: T
authors.lastname: Caruso
authors.forename: Andrea
authors.initials: A
authors.lastname: Peluso
mesh_terms: D000225:Adenine / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D000225:Adenine