Lanthanide contraction and anion-controlled structure diversity in two types of novel 3d-4f heterometallic coordination polymers: Crystal structure and magnetic properties

Abstract

Solvothermal reactions of isonicotinic acid (HIN) with lanthanide nitrate and cuprous halide yielded seven three-dimensional (3D) 3d-4f heterometallic coordination polymers (HCPs). These HCPs are formulated as {[NH2(CH3)2]2LnCu2Br(IN)6∙(DMA)2}n (Ln = Sm(1), Eu(2), Gd(3), Tb(4), Dy(5)) and [LnCu(IN)4∙DMA]n (Ln = Er(6), Yb(7)). Compounds 1–5 possess anionic three-dimensional pillared-layer frameworks with pcu topology, while compounds 6–7 show a rare 3d-4f dia-type two-fold interpenetrating framework with one dimensional square channels with side length of about 9.0 Å along the a axis. Crystal structure analysis reveals that the structure diversity is attributed to the synergistic effect of lanthanide contraction and halide anions. In addition, the magnetic properties of 1, 3, 4 and 5 were investigated.