Squaramide-based reagent for selective chromogenic sensing of Cu(II) through a zwitterion radical

Org Lett. 2010 Sep 3;12(17):3840-3. doi: 10.1021/ol101514y.

Abstract

A minimalist squaramide-based chemodosimeter for Cu(2+) is described. Upon selective chelation to 2, Cu(2+) induces the formation of a highly colored zwitterionic radical, which is kinetically stable for hours. The presence of a radical is confirmed by EPR and ESI-MS. It is then possible to use reagent 2 for visual and selective sensing of Cu(2+) at neutral pH.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amides / chemistry*
  • Chelating Agents / chemistry*
  • Copper / analysis
  • Copper / chemistry*
  • Cyclobutanes / chemistry*
  • Electron Spin Resonance Spectroscopy
  • Free Radicals / chemistry
  • Hydrogen-Ion Concentration
  • Oxidation-Reduction
  • Water / chemistry

Substances

  • Amides
  • Chelating Agents
  • Cyclobutanes
  • Free Radicals
  • Water
  • Copper
  • squaric acid