Preparations, structures and properties of heterobimetallic complexes based on tetrahydrofuran-2,3,4,5-tetracarboxylate

Transition heterobimetallic metal-organic frameworks based on tetrahydrofuran-2,3,4,5-tetracarboxylicate (FTA), namely [M(H2O)6][Cu2M(FTA)2(H2O)2]·4H2O [M=Mn (1), Co (2)], and [CuZn(FTA)(H2O)5]·H2O (3) have been synthesized and characterized. Single-crystal X-ray diffraction indicates that complexes 1 and 2 are isomorphic. In 1 and 2, FTA ligand links the metal ions to a 2-D wave-like negative-charged layer with a topology of {4;62}2{4;63;82}2{6}. They possess 1-D channels with [M(H2O)6]2+ and lattice water molecules enclathrated. While in the complex 3, Cu2+ and Zn2+ ions are bridged by FTA to a 2-D neutral layer structure with a {8}2{84;122} topology. Magnetic properties of 1–3 were analyzed in connection with their structures, which show that there exist weak antiferromagnetic interactions between metal ions.

Graphical abstractThree heterobimetallic MOFs were constructed through the size-selectivity of TFA coordination sites for different transition metal ions based on the concept of “Hard and Soft Acids and Bases”.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Complexes 1 and 3 contain 2-D wave-like negative-charged layers. ► Complex 2 is a 2-D neutral layer structure with a {8}2{84;122} topology. ► Complexes 1–3 are the first example of heterobimetallic MOFs based on FTA. ► The coordination sites of FTA show size-selectivity to metal ions.