Colorimetric sensing and anion recognition by Kalanchoe flower-like ligand and its transition metal complexes with polarized N-H interaction motifs

Abstract Herein we report the selective sensing of fluoride ion with kalanchoe flower-like ligand, L ( 2‑chloro‑3‑((3‑dimethylamino)propylamino)naphthalene‑1,4‑dione) and it's metal (K1-Cu(II), K2-Co(II), K3-Zn(II)) complexes. The morphology and anion sensing properties of the L and K1-K3 compounds were investigated with microscopic and spectroscopic techniques. 1H NMR titration was carried out to understand the fluoride ion interaction with the N-H interacting site of the ligand and its metal complexes. Furthermore, quantum chemical calculations were conducted to rationalize the interaction between chemosensors and anions.