Three novel lanthanide MOFs constructed from 1,3-benzenedicarboxylic acid and 1,10-phenanthroline: Hydrothermal synthesis, crystal structure and thermal properties

Three lanthanide based metal–organic frameworks, [Ln2(bdc)3(phen)H2O]·H2O (Ln = La(1), Pr(2) and Yb(3)) were obtained from 1,3-benzenedicarboxylic acid (H2bdc), 1,10-phenanthroline (phen) and corresponding lanthanide(III) salts by hydrothermal synthesis. Single-crystal X-ray diffraction reveals that 1–3 are isomorphous and isostructural, composed of 2-D sheets constructed from dbc and lanthanide ions, and further extended to 3-D supramolecular framework through π–π interactions between phen rings of the neighboring chains. In all of the three MOFs, bdc act as both tetra-monodentate ligand to link two Ln1 and two Ln2 ions (Ln = La(1), Pr(2) and Yb(3)) respectively, and counter-ions to balance the charge of the title complexes. Thermogravimetric analyses of 1–3 display a considerable thermal stability.