Journal of the American Chemical Society, Vol.122, No.37, 9014-9018, 2000
Probing electrostatic effects: Formation and characterization of zwitterionic ions and their "neutral" counterparts in the gas phase
A dipolar ion and its nonzwitterionic counterpart were generated and characterized in the gas phase. A single charge site is found to be sufficient to lower the energy of a zwitterion well below its neutral counterpart. Charge separation in a dipolar anion enables hydrogen-deuterium exchange to take place with acids over an extraordinarily large range. These results provide a basis for studying electrostatic effects and understanding mass spectroscopic processes involving large biological molecules.