Molecular beam study of the reactions of K and Cs with UF6, WF6, MoF6, TeF6, and SeF6

Abstract

The reactions of K and Cs with UF₆, WF₆, MoF₆, TeF₆, SeF₆, and SF₆ at thermal energies have been investigated using crossed molecular beams. Except for SF₆, these hexafluorides have remarkably high electron affinities. In fact, the electron affinities of MoF₆, WF₆, and UF₆ exceed the ionization potentials of K and Cs so that spontaneous ion pair formation is energetically possible. In no case was a significant ion current observed. Instead, exchange reactions to form MF (and possibly MAF₅) are observed. The measured product angular distributions were in all cases found to be consistent with the model of complex formation. However, substantial differences in the nature of the complex disintegration were noted.