The chemistry of some low energy C5H9O+ oxonium ions

The reactions of the low energy oxonium ions CH3CHCHC+(H)OCH3, b1+, CH2CHC+(CH3)OCH3, b2+, and CH2C(CH3)C+(H)OCH3, b3+, are reported and compared with those of their 1,3-H shift isomers CH3CHCHCH2OCH2+, b4+, CH2CHCH(CH3)OCH2+, b5+, and CH2C(CH3)CH2OCH2+, b6+. The metastable ion (MI) spectrum of the C4H6OCH3+ ions b1+– b3+ is dominated by loss of CH2O. Elimination of C3H6, which is associated with a composite metastable peak, is also …