Theoretical studies on magnetic interactions between Cu(II) ions in hydroxypyridone nucleobases

摘要

The origin of a ferromagnetic interaction between Cu2+ ions in the Cu2+-DNA system which reported by Tanaka et al. is examined by using DFT calculations. In order to consider effects of an entanglement and a dis-entanglement of the double helix chain, three types of structural disorders i.e. distance, rotation angle and discrepancy in XY-plane, are considered in the model dimer structure. All calculated results show that J(ab) values are weak anti-ferromagnetic couplings. Boltzmann distribution simulation indicates that the high spin (HS) species exist 21% at 1.5 K by thermal excitation within the model structure.