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

Abstract

Two tetranuclear Ni–Ln nanoclusters [Ni2Ln2(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 Ni2+ ion. 1 and 2 have planar structures and their molecular sizes are about 6 × 11 × 19 Å. Upon the excitation of ligand-centered absorption, 2 exhibits the typical NIR luminescence of Yb3+. The lanthanide luminescence lifetime (τ) and quantum yield (Φem) of 2 in CH3CN are 5.18 μs and 0.04%, respectively.