Diaminomaleonitrile Based Hybrid Receptor for Selective Colorimetric Sensing of Dihydrogen Phosphate and Fluoride Ions

Abstract

A diaminomaleonitrile based hybrid receptor (A1) derived from 2-hydroxy-1-naphthaldehyde and substituted pyrazole derivative (1a) was successfully synthesized and characterized. The hybrid receptor (A1) showed instant colorimetric change to deep orange from light yellow with bathochromic shifts upon interaction with both fluoride and dihydrogen phosphate ions. Further, UV-Visible studies revealed that receptor (A1) selectively senses fluoride and dihydrogen phosphate ions in comparison to PF–6, HSO –4, ClO–4, Cl–, Br– and I– ions. Also, receptor (A1) act as 'turn off' fluorescent switch for both fluoride and dihydrogen phosphate ions. Moreover, synthesized sensor (A1) can sense fluoride and dihydrogen phosphate ions in detection range of 10 –6–10–7 M.