Chemical Reactions and Collisional Quenching of the Chromium Atomic Ion in a Metastable Excited State

Article abstract of DOI:10.1021/j100272a018

The kinetics of reaction between Cr⁺ produced by 70-eV electron impact on Cr(CO)6 are described.Approximately 26percent of the Cr⁺ ions react at a rate 4.4 times slower than the remaining Cr⁺ ions.This is interpreted in terms of an excited state that is long lived on the time scale of the experiment (2 s).The variation of ion abundance with time in a mixture of Cr(CO)6 and CH4 following a pulse of 70-eV electrons is analyzed.The analysis indicates that the excited state reacts with CH4 to form CrCH2⁺ but that the primary results of collision between the excited Cr⁺ and CH4 is quenching of the excited state.If the quenching process produces ground-state Cr⁺ rather than another excited state, it is spin forbidden.Collision-induced decomposition of CrCH4⁺ supports the involvement of an excited state in the reaction which produces CrCH2⁺.The CrCH2⁺ ion was not observed to react with CO.The possibility that Fe⁺ formed by electron impact on Fe(CO)5 includes ions in metastable states is discussed.