A New 2D Europium(III) Coordination Polymer Based on 4-Bromoisophthalate Ligand: Synthesis, X-ray Structure, Luminescent and Magnetic Properties

A new 2D europium coordination polymer, {[Eu 2 (Bript) 3 (H 2 O) 2 ]·2(H 2 O)} n ( 1 ) [H 2 Bript = 4-bromoisophthalic acid], was prepared by hydrothermal synthesis and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. The carboxylate oxygen atoms of Bript ligands link the neighboring Eu(III) ions to form a Eu(III)–carboxylate chain with the Eu⋯Eu separations of 3.982 and 5.585 Å, which the chains are further extend into a two-dimensional network. The 3D fluorescence spectra of 1 were detected at room temperature under the excitation and emission wavelengths range of 250–450 and 420–750 nm with the same interval of 5 nm, respectively. The lifetime of 1 in solid-state at room temperature is up to 0.935 ms. The magnetic result shows an antiferromagnetic coupling between the paramagnetic metal cations. Moreover, in vitro MTT assays at different concentrations of 1 have also been investigated and the results reveal that complex 1 was low cytotoxic.