Two magnetic lanthanide–organic frameworks based on semi-rigid tripodal multicarboxylate ligand and different rod-shaped SBUs

• Two magnetic 3-D LnIII MOFs constructed from tripodal multicarboxylate
• Different infinite 1-D rod-shaped inorganic [Lnx(COO)y(H2O)z] SBUs
• Offering effective means for constructing unique MOFs

Assembly of a semi-rigid tripodal ligand, 3,5-bis(4-carboxyphenoxy)benzoic acid (H3bpa), with Ln2O3 (Ln = Dy for 1 and Er for 2) under hydrothermal condition produces two three-dimensional (3-D) lanthanide–organic frameworks (LnOFs), [Dy2(bpa)2(H2O)3] (1) and [Er4(bpa)4(H2O)6](H2O) (2). Single crystal X-ray diffraction indicates that LnOFs 1 and 2 involve different one-dimensional (1-D) rod-shaped metal-carboxylate secondary building units (SBUs), which are further extended to afford two different 3-D frameworks via the linkage of bpa3 − ligands. The results demonstrate that the diverse conformations and coordination modes of bpa3 − ligands play a key role on the formation of the final framework structures. Temperature-dependent magnetic susceptibility measurements reveal the presence of LnIII⋯LnIII ferromagnetic interactions in both LnOFs.

The construction of two magnetic 3-D DyIII and ErIII lanthanide–organic frameworks has been successfully achieved based on 3,5-bis(4-carboxyphenoxy)benzoate, and their diverse framework structures can be well regulated by different infinite 1-D rod-shaped inorganic [Lnx(COO)y(H2O)z] SBUs.Figure optionsDownload as PowerPoint slide