Harvesting 18F-fluoride ions in water via direct 18F–19F isotopic exchange: radiofluorination of zwitterionic aryltrifluoroborates and in vivo stability studies

In this report, we show that [18F]-zwitterionic aryltrifluoroborates with ortho-phosphonium groups are: (i) easily accessible via direct 18F–19F isotopic exchange reactions in aqueous solutions; and (ii) efficiently stabilized in vivo against fluoride ion dissociation.