Captodative substituted C4H7O+2 carbenium ions and their relationship with the proton-bound complex CH3CHO ţuH+ ţCCH2CO

The carboxy propylium ions CH3CH2C+HCOOH, CH3C+HCH2COOH and (CH3)2C+COOH have been generated in the gas phase by loss of I. from the respective ionized iodo acids. The straight chain isomers interconvert rapidly with themselves and with CH2CHCH2C+(OH)2. The major unimolecular dissociation products are CH3CHCHC+O + H2O and CH3C+O + CH3CHO, together with some CH3C+HOH + CH2CO. Loss of H2O is proposed to occur directly from …