title: From an icosahedron to a plane: flattening dodecaiodo-dodecaborate by successive stripping of iodine.
abstract: It has been shown by electrospray ionization-ion-trap mass spectrometry that B(12)I(12)(2-) converts to an intact B(12) cluster as a result of successive stripping of single iodine radicals or ions. Herein, the structure and stability of all intermediate B(12)I(n)(-) species (n=11 to 1) determined by means of first-principles calculations are reported. The initial predominant loss of an iodine radical occurs most probably via the triplet state of B(12)I(12)(2-), and the reaction path for loss of an iodide ion from the singlet state crosses that from the triplet state. Experimentally, the boron clusters resulting from B(12)I(12)(2-) through loss of either iodide or iodine occur at the same excitation energy in the ion trap. It is shown that the icosahedral B(12) unit commonly observed in dodecaborate compounds is destabilized while losing iodine. The boron framework opens to nonicosahedral structures with five to seven iodine atoms left. The temperature of the ions has a considerable influence on the relative stability near the opening of the clusters. The most stable structures with five to seven iodine atoms are neither planar nor icosahedral.
authors.affiliation: Institut de Ciència de Materials de Barcelona ICMAB-CSIC, 08193 Bellaterra, Spain.
authors.forename: Pau
authors.initials: P
authors.lastname: Farràs
authors.forename: Nina
authors.initials: N
authors.lastname: Vankova
authors.forename: Lei Liu
authors.initials: LL
authors.lastname: Zeonjuk
authors.forename: Jonas
authors.initials: J
authors.lastname: Warneke
authors.forename: Thomas
authors.initials: T
authors.lastname: Dülcks
authors.forename: Thomas
authors.initials: T
authors.lastname: Heine
authors.forename: Clara
authors.initials: C
authors.lastname: Viñas
authors.forename: Francesc
authors.initials: F
authors.lastname: Teixidor
authors.forename: Detlef
authors.initials: D
authors.lastname: Gabel