Three types of lanthanide coordination polymers from 1D to 3D based on a tetracarboxylate ligand: synthesis, structural diversities and properties

Three types of lanthanide coordination polymers with the formulas [Ln(Habtc)(H2O)(DMA)](n) (1-3) {Ln = Ho (1), Er (2), Tm (3)}, [Ln(Habtc)(H2O)(2)(DMF)](n) (4-6) {Ln = Gd (4), Er (5), Tm (6)} and {[(CH3)(2)NH2][(H(2)abtc)(2)Ln(H2O)]center dot 5H(2)O}(n) {Ln = Gd (7), Dy (8), Er (9), Tm (10)} were constructed under solvothermal conditions in the presence of 3,3', 5,5'-azobenzenetetracarboxylic acid (H(4)abtc). They have three structural types from 3D to 1D polymers. The structural features of the three types of Ln-CPs are as follows: 1-3 shows a three-dimensional (3D) framework with an sni-type topology. Compounds 4-6 form a 2D sheet-like extended structure and these sheets stack on each other to give a 3D supramolecular architecture. The structures of 7-10 can be described as 1D chains constructed from Ln(3+) ions and H(2)abtc(2-) ligands. The versatile structures well exhibit the rich coordination chemistry of H(4)abtc and the coordination geometries of Ln(III) ions. In addition, the magnetic and luminescence properties of complex 8 were investigated. Luminescent selective and sensitive sensing of Cr3+ compared with other metal ions was investigated by using 8. Moreover, the 1D anionic lanthanide coordination polymer 10 presents highly selective adsorption of cationic dyes via ion-exchange processes. The results show that H(4)abtc is a good ligand for constructing CPs with varying structures and properties.