Construction of luminescent tetranuclear Ni–Ln (Ln = Eu and Yb) Schiff base nanoclusters

Abstract Two tetranuclear Ni–Ln nanoclusters [Ni 2 Ln 2 (L) 2 (OAc) 6 ] (Ln = Eu ( 1 ) and Yb ( 2 )) were synthesized by the using of a new Schiff base ligand with Ph-S-Ph backbone. The sulfur atom of the Schiff base ligand is coordinated with the Ni 2+ ion. 1 and 2 have planar structures and their molecular sizes are about 6 × 11 × 19 A. Upon the excitation of ligand-centered absorption, 2 exhibits the typical NIR luminescence of Yb 3+ . The lanthanide luminescence lifetime ( τ ) and quantum yield (Φ em ) of 2 in CH 3 CN are 5.18 μs and 0.04%, respectively.