This is a new joint paper with our friend Prof. Dr. David Díaz Díaz (Universität Regensburg) and his collaborators, which delves into the properties and applications of aminoindanol urea derivative: a fascinating molecule that has been already more than 10 years present in our research devoted to the organocatalysis .

Two years ago a comprehensive study about its capacity of forming supramolecular gels was accomplished (Chem. Eur. J. 2014, 20, 10720-10731). Now, its ability to selectively recognize fluoride anion among other halides, has just been published. This article is part of the special issue: “Colorimetric and Fluorescent Sensor“.

Congratulations and thank you very much!

Fluoride anion recognition by a multifunctional urea derivative: An experimental and theoretical study. Schiller , J.; Pérez-Ruiz , R.; Sampedro, D.; Marqués-López, E.; Herrera, R. P.; Díaz Díaz, D. Sensors 2016, 16(5), 658. DOI: 10.3390/s16050658.

Abstract. In this work we demonstrate the ability of a multifaceted N,N′-disubstituted urea to selectively recognize fluoride anion (F⁻) among other halides. This additional function is now added to its already reported organocatalytic and organogelator properties. The signaling mechanism relies on the formation of a charge-transfer (CT) complex between the urea-based sensor and F⁻ in the ground state with a high association constant as demonstrated by absorption and fluorescence spectroscopy. The nature of the hydrogen bonding interaction between the sensor and F⁻ was established by ¹H-NMR studies and theoretical calculations. Moreover, the recovery of the sensor was achieved by addition of methanol.

Key words. fluoride; anion recognition; sensor; N,N′-disubstituted urea; charge-transfer complex; association constant; absorption spectroscopy; fluorescence spectroscopy