A Series of Copper-Lanthanide Heterometallic Coordination Polymers Derived from Pyridine-2,3-dicarboxylic Acid and in situ Generated Succinic Acid.

A series of copper-lanthanide heterometallic coordination polymers (CPs), [LnCu(2,3-pydc)2(suc)0.5(H2O)3] ·H2O [Ln = La ( 1), Pr ( 2), Nd ( 3), Sm ( 4), Gd ( 5), and Eu ( 6), 2,3-H2pydc = pyridine-2,3-dicarboxylic acid, H2suc = succinic acid], [Ln2Cu3(2,3-pydc)6(H2O)10] ·8H2O [Ln = Eu ( 7), Tb ( 8), Dy ( 9), and Er ( 10)], and [Ln2Cu(2,3-pydc)2(suc)(µ2-OH)2(H2O)2] ·2H2O [Ln = Er ( 11), Yb ( 12), and Lu ( 13)], were synthesized by the hydrothermal reactions of LnCl3 · nH2O, Cu(NO3)2 ·3H2O, pyridine-2,3-dicarboxylic acid (2,3-H2pydc), and N, N′-di(4 H-1,2,4-triazole)butanamide (dtb). CPs 1- 13 possess three types of three-dimensional (3D) frameworks. In 1- 6, the dinuclear Cu2(2,3-pydc)4 and Ln2(COO)2 units link to each other to form two-dimensional (2D) layers, which are extended by the suc anions into a 3D framework. In 7- 10, the lanthanide ions connect the trinuclear Cu3(2,3-pydc)6 units into a 3D framework. In 11- 13, the mononuclear Cu(2,3-pydc)2 units bridge the one-dimensional (1D) lanthanide chains into 2D layers, which are linked by the suc anions into a 3D framework. CP 9 shows a field-induced slow magnetic relaxation behavior with a Ueff value of 83.7 K. [ABSTRACT FROM AUTHOR]