A novel three-dimensional 3d–4f heterometallic coordination polymer with unique (3,4)-connected topology and helical units: Synthesis, crystal structure and photoluminescence property

One new three-dimensional 3d–4f heterometallic coordination polymer, namely, {[EuZn2(imdc)2(C2O4)0.5(H2O)4]·2H2O}n (1) (H3imdc = imidazole-4,5-dicarboxylic acid), has been successfully synthesized by the hydrothermal reactions of Eu2O3, Zn(NO3)2·6H2O, H3imdc, H2C2O4·2H2O and H2O. Single-crystal X-ray diffraction analysis reveals that complex 1 possesses 3D heterometallic framework containing 2D layer based on L–Zn2–L (L = imdc) helical chains and L–EuZn1–L chains. Complex 1 exhibits unprecedented (3,4)-connected four-nodal topology with Schläfli symbol (6·7·8) (6·7·9) (6·72·82·10) (7·82). Moreover, the photoluminescence property of 1 was investigated in the solid-state at room temperature.