Synthesis of a Phenylhydrazone‐based Colorimetric Anion Sensor with Complementary IMP/INH Logic Functions

Abstract

AbstractA dinitrophenyl hydrazone colorimetric anion sensor (receptor 1) was synthesized and its recognition properties towards various anions were investigated by naked eye observation and spectroscopic methods, namely UV‐vis and 1H NMR titrations in DMSO. The addition of AcO−, F− and H2PO4− to receptor 1 resulted in marked red shift of the charge‐transfer absorbance band (Δλ=91 nm, 407 nm to 498 nm) concomitant with a 'naked‐eye' detectable colour change from yellow to pink. However, both the colour and spectral changes were reversible by the addition of cations (MII) of 3d5‐10 as well as CdII, HgII, MgII and CaII. Subsequently, complementary IMP/INH logic functions based on colour and spectral switching (ON/OFF) were affirmed. The sensor can, thus be utilized as a colorimetric molecular switch modulated by F−/MII.