  DNA base-gold interactions are studied theoretically at the DFT level using
Au3 and Au4 clusters as simple catalytic models for Au particles. The bonding
between DNA bases and gold clusters occurs via the anchoring of a Au atom to
the N or O atoms of the bases. In the most stable planar base-Au3 complexes,
the Au-N or Au-O anchor bonds are reinforced by N-H...Au bonds. The mechanism
of formation of these nonconventional H-bonds is discussed.
