An excess electron connects uracil to glycine: Ab-initio study

In recent work Gutowski et al. [Eur. Phys. J. D 20, 431 (2002)] reported photoelectron-spectroscopy and theoretical study of covalent anion of the uracil-glycine complex. In present work we use ab initio calculations to describe an anionic complex of uracil and glycine where the excess electron is localized in a diffuse state between the two monomers. In this system the uracil and glycine molecules are separated by about 4.5 Å and the dipoles of the two monomers point at the excess electron located in the middle of the complex. The calculated fragmentation energy of the anion into a dipole-bound uracil anion and a neutral glycine molecule is 1.7 kcal/mol.