Evaluation of steric and substituent effects in phenols by competitive reactions of dimethyl ether ions in a quadrupole ion trap.
Competitive reactions of dimethyl ether ions are used to probe the steric and substituent effects of substituted phenols and anisoles in a quadrupole ion trap. The relative percentages of protonation and methylene substitution from the reactions of dimethyl ether ions show a correlation with size, location, and number of subsrituents on the aromatic ring. Although gas-phase basicity measurements of the phenols show no discernible correlation with the percentages of competitive reactions, semiempirical calculations show a good correlation between the trend in heats of formation and the trend in methylene substitution percentage. Reactions with deuterated compounds show that the methylene substitution reaction occurs on the ring.
Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas, USA.
G F
GF
Bauerle
J S
JS
Brodbelt