Anion-dependent construction of two hexanuclear 3d–4f complexes with a flexible Schiff base ligand

Abstract

Two hexanuclear 3d–4f Ni–Eu and Cu–Eu complexes [Eu₄Ni₂L₂(OAc)₁₂(EtOH)₂] (1) and [Eu₄Cu₂L₂(OAc)₁₂]·2H₂O (2) are reported which are formed from the salen type Schiff-base ligand H₂L (H₂L = N,N′-bis(3-methoxysalicylidene)butane-1,4-diamine). In both complexes, four Eu³⁺ cations are bridged by eight OAc⁻ groups and the chain is terminated at each end by two ML (M = Ni and Cu) units. The structures of 1 and 2 were determined by single crystal X-ray crystallographic studies and the luminescence properties of the free ligand and metal complexes in solution were measured.