The luminescence properties of the tetranuclear bimetallic lanthanide complexes Sm 2 Eu 2 (1) and Eu 2 Tb 2 (2), were compared with those of the analogous homometallic complexes [Sm 4 (μ 3 -OH) 2 (salen) 2 (acac) 6 (CH 3 OH) 2 ]·CH 3 OH(3) and [Eu 4 (μ 3 -OH) 2 (salen) 2 (acac) 6 (CH 3 OH) 2 ] (4) [H 2 salen = N,NЈ-ethylenebis(salicylideneimine), Hacac = acetylacetonate]. X-ray crystallographic analysis reveals that complexes 3 and 4 have planar tetranu-* Dr. T. Gao