Synthesis of Isophorone based D-π-A Type Chemosensor for the Response of Hg²⁺

Abstract

A new bifunctional probe based on indole-isophorone conjugate for the distinct response of Hg²⁺ and F⁻ ion was demonstrated for the first time. The sensing property of 3 with F⁻ ion is due to the formation of H-bonds between F⁻ ion and NH moiety which has been enhanced ICT between NH and isoporone unit. Sensing mechanism of Hg²⁺ has also been confirmed by competitive experiment. The association constant were found to be 5.89×10⁴ and 1.15×10⁴ M⁻¹ for the 3-Hg²⁺ and 3-F⁻, respectively. Theoretical calculation was performed to explain the optical sensing property of 3 with Hg²⁺ and F⁻ ion.

Keywords:

• Isophorone
• Indole
• Intramolecular charge transfer (ICT)
• Push
• Pull
• π conjugation
• Computational calculation

Acknowledgments

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2014002985)