Synthesis and anion-sensing property of a family of Ru(II)-based receptors containing functionalized polypyridine as binding site

A family of fluoroionophores have been synthesized incorporating Ru(II)-bipyridine moiety as fluorogenic unit and amino/benzenesulphonamido functionalized 1,10-phenanthroline moiety, attached to Ru(II), as binding sites. Two of the ligands and one of the complexes have been characterized crystallographically. Anion recognition property, studied by luminescence, UV–vis and 1H NMR spectroscopy, with a large number of anions exhibit strong complexation with F−, H2PO4− and AcO−. Binding constants have been determined from luminescence titration and 1H NMR study gave insight about binding site of anions. Bidentate chelating nature of the H2PO4− and AcO− anions and steric crowding created by benzenesulphonamide moiety has significantly influenced binding constants and selectivity.