Quantum chemical study of hole transfer coupling in nucleic acid base complexes containing 7-deazaadenine

In this study, we report on the results of MD/QM computations of charge–transfer integrals for nucleic acid base complexes in stacked configurations containing 7-deazaadenine. A strong dependence of charge–transfer integrals on torsional parameters was observed in case of all studied complexes. However, a very important finding of this study is that in proximity of equilibrium configuration, the values of charge–transfer integral are not sensitive to the replacement of adenine with 7-deazaadenine. Likewise, the analysis of distribution of charge–transfer integrals, determined for structures taken from molecular dynamics simulations, revealed that their changes upon adenine modification are not a key factor influencing charge transport.