Research Update: Density functional theory investigation of the interactions of silver nanoclusters with guanine

Bare and guanine-complexed silver clusters Ag-n(z) (n = 2-6; z = 0-2) are examined using density functional theory to elucidate the geometries and binding motifs that are present experimentally. Whereas the neutral systems remain planar in this size range, a 2D-3D transition occurs at Ag-5 (+) for the cationic system and at Ag-4 (2+) for the dicationic system. Neutral silver clusters can bind with nitrogen 3 or with the pi system of the base. However, positively charged clusters interact with nitrogen 7 and the neighboring carbonyl group. Thus, the cationic silver-DNA clusters present experimentally may preferentially interact at these sites. (C) 2017 Author(s).