Two novel lanthanide(III) organic frameworks based on a biphenyltetracarboxylate ligand: synthesis, structure and magnetic and luminescence properties

摘要

Two new two‐dimensional lanthanide coordination polymers, namely poly[[tetra‐μ 2 ‐acetato‐tetraaquabis(μ 4 ‐biphenyl‐3,3′,5,5′‐tetracarboxylato)tetrakis(dimethylacetamide)tetraterbium(III)] pentahydrate], {[Tb 4 (C 16 H 6 O 8 ) 2 (C 2 H 3 O 2 ) 4 (C 4 H 9 NO) 4 (H 2 O) 4 ]·5H 2 O} n , (1), and poly[[tetra‐μ 2 ‐acetato‐tetraaquabis(μ 5 ‐biphenyl‐3,3′,5,5′‐tetracarboxylato)tetrakis(dimethylacetamide)tetraeuropium(III)] tetrahydrate], {[Eu 4 (C 16 H 6 O 8 ) 2 (C 2 H 3 O 2 ) 4 (C 4 H 9 NO) 4 (H 2 O) 4 ]·4H 2 O} n , (2), have been synthesized from biphenyl‐3,3′,5,5′‐tetracarboxylic acid (H 4 bpt) and Ln(NO 3 ) 3 ·6H 2 O (Ln = Tb and Eu) under solvothermal conditions. Single‐crystal X‐ray structure analysis shows that the two compounds are isostructural and crystallize in the monoclinic P 2 1 / n space group. The crystal structures are constructed from bpt 4? ligands (as linkers) and {Ln 2 (μ 2 ‐CH 3 COO) 2 } building units (as nodes), which topological analysis shows to be a (4,6)‐connected network with sql topology. Compounds (1) and (2) have been characterized by elemental analysis, IR spectroscopy, powder X‐ray diffraction (PXRD), thermogravimetric analysis (TGA) and fluorescence analysis in the solid state. In addition, a magnetic investigation shows the presence of antiferromagnetic interactions in compound (1).