N,N′-Bis-(4-nitrophenylcarbamothioyl)phthalamide

A novel colorimetric receptor linked to two nitrophenylurea groups was synthesized in good yields, characterized and their chromogenic properties investigated towards various anions (F ？, Cl ？, Br ？, I ？, OH ？, AcO ？, H 2PO 4 ？ and CN ？) by UV-Vis techniques. The receptor, effectively and selectively, recognized and distinguished the biologically important F ？ from other anions such as Cl ？, Br ？, I ？ etc. in DMSO. This selectivity could be easily observed by the naked eye, indicating that receptor is potential colorimetric sensor for fluoride ion.