AF-like Ground State of Mn-DNA and Charge Transfer from Fe to Base-π-Band in Fe-DNA

The electronic states of M-DNA doped with M = Mg, Ca, Zn, Mn, Fe are investigated mainly with magnetic properties. In the ”wet” condition the Mn ions of Mn-DNA form a 1-D chain in the center of a DNA double helix, as evidenced from the formation of the unnatural base pair combination with M, poly(dA)-M-poly(dC), but in the ”dry” condition they form a3 -D network with the antiferromagnetic ground state around 0.4 Kw ith the superexchange coupling via water molecules. The valence of 3+ is found only in Fe-DNA, from which the base ! -band obtains ! charge carriers.