Fluorescent PET (photo-induced electron transfer) sensors for alkali metal ions with improved selectivity against protons and with predictable binding constants

Abstract

Alkali metal ions enhance the fluorescence quantum yield of the benzocrown ether derivatives (1c) and (1d) in methanol by factors of ⩽15 with no other visible changes in the electronic spectra and with predictable stability constants for the sensor-cation interaction, whereas protons exert a much smaller influence.