Abstract
Quantum chemical calculations using gradient corrected density functional theory reveals the unusual properties of a platinum (Pt) atom interacting with fluorine (F) and chlorine (Cl) atoms. Up to six F and Cl atoms are bound to a single Pt atom, which results in increase of electron affinities as successive halogen atoms are attached reaching a peak value of 8.05 eV for PtF6 and 6.46 eV for PtCl6. The large HOMO-LUMO energy gap, both in neutral and anionic forms, reveals further evidence of their stability. The unusual properties bring about the involvement of inner shell 5d-electrons, which not only allow PtFn and PtCln (n = 1-6) complexes to belong to the class of superhalogens but also show that its valence can exceed the nominal value of 1. (C) 2011 Elsevier B.V. All rights reserved.