title: Separation of tautomeric forms of [2-nitrophloroglucinol-H]- by an in-electrospray ionization source hydrogen/deuterium exchange approach.
abstract: Here we report the observation that, depending on the solvent used for the electrospray, 2-nitrophloroglucinol undergoes a deprotona- tion from different sites forming two tautomeric gas phase ions. Those ions differ bythe collision-induced dissociation [CID] spectra and by the gas phase hydrogen/deuterium (H/D) exchange kinetic. We performed H/D exchange in the electrospray ionization (ESI) source by saturation ESI region with vapors of deuterated solvent (D20). It was observed that [2-nitrophloroglucinol-H]- exchanges two -OH hydrogens when MeOD is used as the spray solvent but when the spray solvent is 50:50 MeOD/DO20 we observed an additional two H/D exchanges at the aromatic ring. We propose that the reaction occurs via a keto-enolt tautomerization mechanism which was found to be energetically favorable.
authors.forename: Yury
authors.initials: Y
authors.lastname: Kostyukevich
authors.forename: Alexey
authors.initials: A
authors.lastname: Kononikhin
authors.forename: Igor
authors.initials: I
authors.lastname: Popov
authors.forename: Natalia
authors.initials: N
authors.lastname: Starodubtseva
authors.forename: Eugene
authors.initials: E
authors.lastname: Kukaev
authors.forename: Eugene
authors.initials: E
authors.lastname: Nikotaev
mesh_terms: D003903:Deuterium; D041961:Deuterium Exchange Measurement / Q000379:methods*; D006859:Hydrogen; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: C000597873:2-nitrophloroglucinol; D006859:Hydrogen; D003903:Deuterium; D010696:Phloroglucinol