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Abstract: Two novel isostructure open frameworks of Ln(III), [Ln(L)(H2O)·1.5H2O] n , [Ln=Pr(1), Eu(2)], have been successfully synthesized using multifunctional organic compound 7,8,4′-tricarboxymethoxyisoflavone (L) as a linker through hydrothermal technique. Compounds 1 and 2 consist of 2D networks, which are further assembled into 3D architecture with 1D channels constructed by coordination bonds and the lattice water molecules array in lines occupying these voids via hydrogen bonds. In these compounds, L only exhibit one coordination mode coordinating to Ln(III), and four oxygen atoms from two carboxylate groups and two carboxymethoxy groups of one L coordinate to one Ln(III), simultaneously. The thermogravimetric analyses of these compounds show that the coordinated water and lattice water are lost in two steps, and the final residues are lanthanide oxides. [Copyright &y& Elsevier]

• The article we are going to contribute has the following highlights: • Two rare earth metal organic frameworks were synthesized by solvothermal method using zwitterionic 1,3-Bis(1-carboxylatoethyl)imidazolium bromide as ligand. • Complex 2 of Gd(C 9 H 11 N 2 O 4)(C 2 O 4)(H 2 O) (C 9 H 11 N 2 O 4 2‒ = 1,3-Bis(1-carboxylatoethyl) imidazolium ion, C 2 O 4 2- = oxalate) shows antiferromagnetic interactions in the temperature range 2−300 K. Good water-solubility, integrity and stability of 2 significantly different from common complexes grant it great potential in bio-related applications. Two rare earth coordination polymers named {[La 6 (C 9 H 11 N 2 O 4) 11 (H 2 O) 2 (OH) 2 ]⋅Br 5 } n (1) and [Gd(C 9 H 11 N 2 O 4)(C 2 O 4)(H 2 O)] n (2) (C 9 H 11 N 2 O 4 2‒ = 1,3-bis(1-carboxylatoethyl) imidazolium ion, C 2 O 4 2- = oxalate) were solvothermally synthesized using zwitterionic 1,3-bis(1-carboxylatoethyl)imidazolium bromide as ligand. 1 and 2 were both structurally characterized by single crystal X-ray diffraction, and their thermodynamic properties and magnetic properties of 2 were studied. In the 3D structure of 1 , La3+ ions are all ten-coordinated and exhibit three different coordination environments. This 3D structure of 1 is formed by La−O coordination bonds with Br− located in the cavities through H-bond and electrostatic attraction. Different from 1 , all Gd3+ ions in 2 have the same eight-coordinated environment. These two coordination polymers both have good thermostability until 323 °C for 1 and 375 °C for 2 , and then decompose giving rise to La 2 O 3 and Gd 2 O 3 , respectively. The magnetic behaviors of 2 are measured in the temperature range 2–300 K. [Display omitted] [ABSTRACT FROM AUTHOR]