Structures and magnetic properties of two heterometallic Cu(II)–Cd(II) polymers exhibiting antiferromagnetic ordering.

Two novel heterometallic Cu(II)–Cd(II) coordination polymers, two-dimensional (2D) [Cu2Cd(MMA)2(NTA)2(H2O)2]n (1) and one-dimensional (1D) {[CuCd(MMA)2(H2O)6]·4H2O}n (2), were synthesized with methylmalonic acid (H2MMA) and nicotinic acid (HNTA) as mixed reactants under the conditions of 100 °C and room temperature, respectively. Complex 1 has a 2D layer structure consisting of the tetranuclear [Cu2Cd2] cluster-based 1D chain unit and NTA− linker. 2 exhibits a 1D chain structure with the Cu2+ and Cd2+ ions alternately bridged by the MMA2− ligand. Magnetic studies show that the magnetic interactions for the neighboring Cu2+ ions are both antiferromagnetic within and between the [Cu2Cd2] cluster of the 1D chain in 1 (Jd = −1.39(1) cm−1 and Jc = −1.77(1) cm−1) and there is predominantly ferromagnetic coupling in the 1D chain of 2 (J = 4.96(1) cm−1). Furthermore, 1 displayed antiferromagnetic ordering at lower temperature with TN = 4.0 K. [ABSTRACT FROM AUTHOR]