Solvent-dependent “turn-on” fluorescence chemosensor for Mg2+ based on combination of CN isomerization and inhibition of ESIPT mechanisms

A fluorescent chemosensor (L) for Mg2+ has been synthesized and characterized. It exhibits turn-on fluorescence response for Mg2+ only in alcohol solvent with high sensitivity and selectivity. The mechanism aspect concerning the remarkable fluorescence response was discussed by optical measurements, LC-MS/MS and HPLC-FLD of L and L with Mg2+ ions in solvents.