Loss of Alkanes from Ionized Branched Chain Ethers. Metastable Decomposition from an Electronically Excited State?

Article abstract of DOI:10.1021/j100439a006

Ethers of the type R¹CH(CH3)OR² show a metastable peak for the loss of R¹H in their mass spectra.Loss of C2H5D is the principal decomposition of metastable C2H5CH(CD3)O(+.)CH3, demonstrating that vinyl ether ions are formed by the metastable losses of alkanes.Thermochemical and orbital symmetry considerations support the hypothesis that the losses of alkanes occur from an electronically excited state of the ether ions.Other ether ions with the oxygen bonded to a nonterminal carbon also lose alkanes.N,N-Dimethyl-s-butylamine, di-sec-butyl sulfide, sec-butylbenzene, and tert-pentyl ether ions do not lose alkanes.