The association of uracil dimers and copper(II) has been studied through the use of B3LYP/6-311+G(3df,2p)//6-31+G(d,p) calculations. Although uracil-Cu(2+) complexes have never been experimentally detected, our results show that [(uracil)2-Cu](2+) is thermodynamically stable with regard to both the proton loss and the fragmentation into (uracil)2(+)˙ + Cu(+), although it is metastable with resp...