Rare cis‐Dioxido Uranyl Framework Crystalline Complexes: Synthesis, Structure, Characterization and Properties

The trans‐dioxido uranyl frameworks named as [(UO 2 )(Aip)(DMA)] (1) , H[(UO 2 )(Aib) 3 ] (2) and rare cis‐dioxido [(UO 2 )Co(Suc) 2 (H 2 O) 4 ] (3) , and [(UO 2 )Ni(Suc) 2 (H 2 O) 4 ] (4) have been synthesized, which based on 5‐aminoisophthalic acid (H 2 Aip), 3‐aminobenzoic acid (HAib), and succinic acid (H 2 Suc) as ligands. They were characterized by Fourier Transform Infrared spectra, UV‐vis absorption spectra, single‐crystal X‐ray diffraction, powder X‐ray diffraction and thermogravimetry analysis. It was found that uranium ion of the complex 1 is in the pentagonal bipyramidal coordination environment, while those of the complexes 2 – 4 are in the hexagonal bipyramidal coordination environment. Complexes 1 , 3 , and 4 are 3D network structures, 2 is a discrete structure. In particular, geometry of O=U=O for 1 and 2 are trans, ones for 3 and 4 are cis. The highest removal rate of methylene blue was almost to 96 % by complex 1 as an adsorbent, which illustrates that potential application on dye adsorption.