KINETIC STUDIES AND DETERMINATION OF PROTON AFFINITY DIFFERENCES WITH ESI/FT-ICR MS TO INVESTIGATE THE 'REVERSE ANOMERIC EFFECT' IN GAS PHASE

摘要

1. Kinetic studies can be used to differentiate alpha-GIA and beta-GIA anomers and investigate the existence of RAE in a solvent free gas phase environment. 2. Proton transfer from TEA and TMA to alpha and beta anomers, at various pressure ranges, reveals two different chemical reactivities for the alpha (axial at C-1) and beta (equatorial at C-1) anomers of acetylated glucopyranosylimidazoles; alpha-GIA has higher GB than beta-GIA. 3. To improve proton transfer reaction rate constant accuracies and precisions for the two anomers, proton transfer from additional neutral reagents under better controlled pressures will be required. 4. GB bracketing yields estimated preliminary GB values for alpha-GIA and beta-GIA anomers between 196.3 kcal mol-1 and 214.1 kcal mol-1.