Fragmentation of valence electronic states of CF+4 and SF+6 studied by threshold photoelectron-photoion coincidence spectroscopy

Fragmentation of Energy-Selected SF5CF3+ Probed by Threshold Photoelectron Photoion Coincidence Spectroscopy: Bond Dissociation Energy of SF5-CF3 and Its Atmospheric Implications

“…With SF 5 CF 3 , it is essentially a S−C σ-bonding orbital, 34 whereas the HOMO of both CF 4 and SF 6 is a F 2pπ non-bonding orbital with an ionisation energy similar to that of an isolated fluorine atom. 8,35 Over the range 80 to 97 nm (12.8 to 15. This value is significantly lower than that quoted in the most recent JANAF tables, -1700 ± 63 kJ mol -1 .…”

A Selected Ion Flow Tube Study of the Reactions of Several Cations with the Group 6B Hexafluorides SF6, SeF6, and TeF6

“…7 The recombination energy of F + (17.42 eV) lies on the high-energy shoulder of the B A/ photoelectron band of SF 6 . 7, 31 We may expect that, when non-zero Franck-Condon factors are involved, a long-range (dissociative) charge transfer may take place.…”

“…It is only at 15.33 eV that the photoionisation cross section becomes significant leading to an observed signal. 7,8 This means that for the reactions involving CO + and N + , dissociative charge transfer (if it occurs) can only do so by a short-range rather than a long-range mechanism. 4,6,12,23,[26][27][28][29][30] A long-range mechanism requires energy resonance with non-zero Franck-Condon factors and no distortion of the potential energy curves, with all the available energy going into fragmentation.…”

“…For example, charge (electron) transfer will only be energetically possible for those ions having recombination energies greater than the first dissociative ionisation limit of the XF 6 molecule (X = S, Se or Te), XF 6 XF 5 + + F + e -. The first dissociative ionisation limit is used because threshold photoelectron-photoion coincidence (TPEPICO) studies show that the ground state of XF 6 + is not a stable ion and dissociates to XF 5 + + F. 7,8 (Any bound region of the XF 6 + potential energy surface lies well outside that accessible from the neutral XF 6 ground state.) Even when (dissociative) charge transfer is energetically possible, this constraint does not necessarily guarantee that it will occur.…”

Vacuum Ultraviolet Negative Photoion Spectroscopy of SF5Cl

“…There have been many investigations of the ion chemistry of sulfur hexafluoride, SF 6 , involving production of cations, anions, and chemical reactions, [1][2][3] but relatively few of the derivative molecule sulfur chloropentafluoride, SF 5 Cl. The structure of SF 5 Cl, C 4v symmetry in the gas phase, has been established by microwave spectroscopy 4 and electron diffraction.…”