Anion receptor coordination tripods capped by [9]ane-S3

Abstract

A series of ruthenium(II) complexes with face-capping [9]ane-S₃ ligands are described. The compounds function as supramolecular receptors for anions via three tripodally arranged 3-aminopyridine ligands. The [9]ane-S₃ ligand stabilises the tripodal complexes which are more readily prepared and studied than their π-arene ruthenium(II) analogues. Pyrenyl derivative 4 displays some activity as a photophysical anion sensor but the anion response is complicated by the complexes concentration dependent emission behaviour. The receptors bind common anions in relatively polar media forming both 1 : 1 and 1 : 2 host–anion complexes with the CH⋯anion interactions involving the thioether ring being implicated in anion binding as well as the convention NH donors.