Interaction of Uracil with LiF and Water Studied by Density Functional Theory Study on Anionic Complexes.

We investigated the interactions of uracil with LiF and water using density functional calculations and determined the structures of (Ura)⁻LiF(H₂O)_n (n = 0–6) complexes. In all clusters from n = 0 to 6, Li⁺ of LiF unit binds directly to the O4 site of uracil via electrostatic interaction. (Ura)⁻LiF connects one water molecule via F⁻ to form a sandwich structure. When the water number reaches 2, the interaction strength between uracil and LiF decreased significantly. Li⁺ and F⁻ always stay together that exist as contact ion pairs. Excess electrons were found on C6, C4, and both O sites of uracil in NPA charge studies. [ABSTRACT FROM AUTHOR]