High Valent Mercury Fluoride Ions

Mercury fluoride ions formed during the laser ablation of HgF_2(s) show the formation of six different cluster ion series viz., HgF_n ^± , Hg_n F_n-2 ^± , Hg_n F_n-1 ^± , (HgF)_n ^± , Hg_n F_n+1 ^± , and Hg_n F_n+2 ^± . Among the different ion series, the observation of high valent HgF_n ^± _(n ^± _{=3,4; n} ^- _=6-8) indicates the existence of corresponding molecules which signify the remarkable participation of 5d Hg electrons in the chemical bonding with F atoms and thus make Hg a truly transition metal. Further, molecular orbital calculations show a large HOMO-LUMO energy gap (≥3 eV) and high electron affinity (≥5 eV) that indicates highly stable HgF_n=3,4,6,8 with super halogen properties.