Negative ions of transition metal-halogen clusters
Journal of Chemical Physics
A systematic density functional theory based study of the structure and spectroscopic properties of neutral and negatively charged MX n clusters formed by a transition metal atom M ͑M =Sc,Ti,V͒ and up to seven halogen atoms X ͑X =F,Cl,Br͒ has revealed a number of interesting features: ͑1͒ Halogen atoms are bound chemically to Sc, Ti, and V for n Յ n max , where the maximal valence n max equals to 3, 4, and 5 for Sc, Ti, and V, respectively. For n Ͼ n max , two halogen atoms became dimerized in
... ecame dimerized in the neutral species, while dimerization begins at n = 5, 6, and 7 for negatively charged clusters containing Sc, Ti, and V. ͑2͒ Magnetic moments of the transition metal atoms depend strongly on the number of halogen atoms in a cluster and the cluster charge. ͑3͒ The number of halogen atoms that can be attached to a metal atom exceeds the maximal formal valence of the metal atom. ͑4͒ The electron affinities of the neutral clusters abruptly rise at n = n max , reaching values as high as 7 eV. The corresponding anions could be used in the synthesis of new salts, once appropriate counterions are identified.