Construction of two 2D 3d-4f coordination complexes based on the linkages of left-and right-handed helical chains

Two transition-lanthanide metal-organic coordination polymers, {[CoLn2(Himdc)2(SO4)2(H2O)4]·H2O}n [Ln = Yb (1), Ho (2)] (H3imdc = imidazole-4, 5-dicarboxylic acid), have been synthesized by the hydrothermal reactions of lanthanide oxides, CoSO4·7H2O, H3imdc and H2O. Single-crystal X-ray diffraction analysis reveals that the isostructural complexes 1 and 2 possess unusual 2D wave-like heterometallic layers with 1D (Ln2O2CoO2)n and [Ln2(SO4)2]n inorganic chains constructed by the assembly of 1D left-/right-handed helical L–Ln2Co–L (L = Himdc) chains and SO42− anions, while a 3D framework is formed via hydrogen-bonding interactions interlayer.