Novel gas phase ions. II. [CH2=CHOH/CH3OH]+ and [CH2=CHOH/H2O]+

The title ions are generated by the loss of C 2 H 4 from ionised 4-methoxybutan-1-ol and butan-1,4-diol, respectively, and are best described as complexes between [CH 2 =CHOH] +• and CH 3 OH (dissociation energy 21 kcal mol −1 ) and between ionised vinyl alcohol and H 2 O (dissociation energy ≥ 13 kcal mol −1 ). [Formula: see text] of the ions [CH 2 =CHOH/H 2 O] +• and [CH 2 =CHOH/CH 3 OH] +• were measured as ≤ 110 and 112 kcal mol −1 , respectively.