A series of lanthanide compounds based on mixed aromatic carboxylate ligands: Syntheses, crystal structures and luminescent properties

A series of lanthanide complexes, [LnL(1)L(1/2)(2)(H2O)(2)](n) [Ln = La(1), Sm(2), Gd(3), Eu(4), H2L1 =2,4-bis(4-methylbenzoyl)isophthalic acid and H2L2=2,5-bis(4-methylbenzoyl)terephthalic acid] have been prepared under hydrothermal conditions and characterized by PXRD, IR, elemental analysis and single crystal X-ray diffraction. Complexes 1-4 are isostructural and comprise paddlewheel dinuclear lanthanide secondary building units linked by four carboxylic groups. L-1 ligands link the dinuclear lanthanide building blocks to form one-dimensional double-stranded looplike chains. The chains are further connected together to form two-dimensional layers by L-2. Furthermore, the luminescent properties of 2 and 4 were also studied. (C) 2012 Elsevier B.V. All rights reserved.