Negative ion mass spectrometry and pulsed discharge electron capture detector data for thermal electron attachment to $\mathrm{S}{\mathrm{F}}_6$ are reported. Electron affinities and activation energies for $\mathrm{S}{\mathrm{F}}_6$ and $\mathrm{S}{\mathrm{F}}_5$ are obtained from these data and literature magnetron, swarm, beam, and collisional ionization data. The thermodynamic and kinetic data cover temperatures from $50\text{to}7500\mathrm{K}$. The largest electron affinity of $\mathrm{S}{\mathrm{F}}_6$, $2.60\left(10\right)\mathrm{eV}$ is assigned to the adiabatic electron affinity. The numbers in parentheses indicate uncertainties. Excited state values are (in eV) 2.45(3), 2.20(3), 2.00(3), 1.80(3), 1.60(3), 1.20(3), 1.04(3), 0.80(3), 0.65(3), 0.45(3), 0.35(3), 0.25(3), and 0.10(10). The activation energies range from near zero to $0.65\left(2\right)\mathrm{eV}$. The adiabatic electron affinity of $\mathrm{S}{\mathrm{F}}_5$, $3.85\left(2\right)\mathrm{eV}$ and an excited state value, $2.77\left(5\right)\mathrm{eV}$ are obtained from a kinetic analysis of published magnetron data. The energies for dissociative electron attachment to give $\mathrm{S}{\mathrm{F}}_5(-)$, $\mathrm{F}(-)$, and excited state $\mathrm{S}{\mathrm{F}}_5(-)$ are $0.20\left(11\right)\mathrm{eV}$, $0.65\left(10\right)\mathrm{eV}$, and $1.28\left(11\right)\mathrm{eV}$ from the $\mathrm{S}{\mathrm{F}}_5\text{−}\mathrm{F}$ dissociation energy, the electron affinity of the fluorine atom, and these values. The average relative anion bond orders for the bonding curves is 0.63(2) and for the antibonding curves is 0.30(2). Fourteen Herschbach ionic Morse Person empirical curves are calculated from these data. Six bonding and six antibonding curves are pseudo-two-dimensional cuts through the multidimensional surface. Representative long-range anionic curves are calculated in reaction coordinates analogous to Marcus parabolas.

• Received 24 April 2007

DOI:https://doi.org/10.1103/PhysRevA.76.032508