Lanthanide-based entangled coordination polymers connected by thiophene-2,5-dicarboxylate: solvothermal syntheses, crystal structures, luminescence and magnetic properties

Nine novel coordination polymers (CPs) with the formulas [M 6 (TDA) 9 (DEF) 5 (H 2 O) 3 ] n [M = Ce ( 1 ), Pr ( 2 ), Nd ( 3 ), Sm ( 4 )], [Eu 4 (TDA) 6 (DEF) 3 (H 2 O) 2 ] n ( 5 ), [Gd 2 (TDA) 3 (DEF) 2 ] n ·H 2 O ( 6 ), [Tb 2 (TDA) 3 (DEF) 2 ] n ·0.5H 2 O ( 7 ), [Dy 2 (TDA) 3 (DEF) 2 ] n ·H 2 O ( 8 ) and [Yb 2 (TDA) 3 (DEF) 2 ] n ·0.5H 2 O ( 9 ) (TDA = 2,5-thiophenedicarboxylate anion and DEF = diethylformamide) have been synthesized at different temperatures in a DEF-H 2 O solvent system under solvothermal conditions. All the compounds were characterized by single crystal X-ray diffraction analysis (XRD), Fourier transformation vibrational spectroscopy (FT-IR) and thermal analysis (TGA). Structural analyses of CPs 1-4 reveal that the polymers crystallize in the orthorhombic space group Pna 2 1 and form 3D frameworks with large volumes 10 378.1(5), 10 230.5(5), 10 171.9(5) and 10 077.1(11) Å 3 , respectively. The M( iii ) ions of CPs 1-4 exhibit nine and eight coordination numbers with diverse geometries. Structural analyses of CPs 5 and 6-9 unveil that the polymers crystallize in the monoclinic system, with space groups P 2 1 and P 2/ c , respectively, forming a 3D network. The TDA ligand exhibits two coordination modes [(κ 1 -κ 1 )-(κ 1 -κ 1 )-μ 4 and (κ 2 -κ 1 -μ 2 )-(κ 1 -κ 1 )-μ 5 ] which interconnect the metal ions to generate 3D novel metal-organic frameworks. The luminescence properties of 4 , 5 , 7 and 8 , and the magnetic properties of 6-8 were investigated. Nine novel coordination polymers 1-9 containing thiophene dicarboxylate anion and DEF have been synthesized solvothermally at different temperatures in DEF-H 2 O solvent system.