Synthesis, Characterization, and Fluorescence Studies of a Novel Schiff Base Ligand and Its Zn(II), Ni(II), Co(II), Cu(II) Complexes

Abstract

A novel ligand, N,N′‐bis(2‐hydroxy‐1‐naphthylidene)‐3‐oxa‐1,5‐diaminopentane (H₂L), and its Zn(II), Ni(II), Co(II), Cu(II) complex were synthesized. The structures of the ligand and its complexes were characterized by elemental analyses, MS (Fab), IR spectra and DTA‐TG. The results show that the molecular composition of these complexes is ML · 1/2H₂O and they are tetradentate complexes, in which the metal ions are coordinated by two nitrogen atoms (‐C=N) and two oxygen atoms (Ar–OH). The fluorescence of the ligand and its complexes in different solvents and pH conditions have also been studied in detail. An enhancement of the fluorescence intensity of the ligand can be observed clearly in the presence of Zn(II), but quenching occurs for the other metal ions.