Production of hyperlithiated Li2F by a laser ablation of LiF–Li3N mixture

Lithium-excess binary clusters Li_nF_n−1 (n=2–9) were detected by photoionization time-of-flight mass spectrometry in a supersonic cluster beam generated by a laser ablation of a solid mixture of lithium fluoride and nitride. Laser power dependence of the Li₂F⁺ signal intensity has indicated that the ionization energy of the hyperlithiated Li₂F molecule is lower than 4.66 eV. The theoretical vertical ionization energy obtained by the CCSD(T)/6-311+G(d)//B3LYP/6-311+G(d) calculations are 4.47 eV. No nitrogen-containing clusters were detected. The absence of Li₄N is ascribed to the exothermicity of the reaction, 2Li₃N→N₂+Li₆.