Solvent-dependent "turn-on" fluorescence chemosensor for Mg(2+) based on combination of C=N isomerization and inhibition of ESIPT mechanisms

Spectrochim Acta A Mol Biomol Spectrosc. 2015:149:83-9. doi: 10.1016/j.saa.2015.04.030. Epub 2015 Apr 22.

Abstract

A fluorescent chemosensor (L) for Mg(2+) has been synthesized and characterized, which exhibits turn-on fluorescence response for Mg(2+) only in alcohol solvent (methanol or ethanol) with high sensitivity and selectivity. But in both nonpolar and polar solvents (cyclohexane, DCM, DMSO or MeCN), L showed negligible fluorescent response for Mg(2+). In order to discover the unique phenomenon, optical measurements, liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and a high performance liquid chromatography with a fluorescence detector (HPLC-FLD) of L and L with Mg(2+) ions in solvents were studied. In alcohol solvent, [L+alcohol molecule] was formed and the mechanism aspect of L concerning the remarkable fluorescence response for Mg(2+) has been discussed.

Keywords: Fluorescent chemosensor; Mechanism; Solvent-dependent; Turn-on.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, High Pressure Liquid
  • Crystallography, X-Ray
  • Fluorescence
  • Fluorescent Dyes / chemistry*
  • Isomerism
  • Magnesium / chemistry*
  • Optical Phenomena
  • Protons*
  • Solvents / chemistry*
  • Spectrometry, Fluorescence
  • Spectrometry, Mass, Electrospray Ionization
  • Spectrophotometry, Ultraviolet
  • Tandem Mass Spectrometry

Substances

  • Fluorescent Dyes
  • Protons
  • Solvents
  • Magnesium