Synthesis, structures and physical properties of new 3D lanthanide coordination polymers constructed from 1,2,4,5-benzenetetracarboxylic acid

A series of new 3D coordination polymers Ln2(BTC)1.5(H2O)(DMSO) (LnEu(1), Gd(2), Tb(3), Dy(4), Ho(5)) (H4BTC = 1,2,4,5-benzenetetracarboxylic acid) have been solvothermal synthesized by the reactions of lanthanide ions with 1,2,4,5-benzenetetracarboxylic acid in a DMSO/H2O solution. These compounds possess the same 3D architectures based on dinuclear lanthanide SBUs {Tb2O4} linked by BTC4− anions and exhibit unprecedented 3D topological nets. Compounds 1 and 3 are strong luminescent materials which display characteristic Eu3+ and Tb3+ emission bands in the visible region. The magnetic properties of 2–5 have also been investigated through the measurement of their magnetic susceptibilities over the temperature range of 2–300 K.