Direct assembly of new cobalt(iii)-lanthanide(iii) heterometallic frameworks with NaCl-like topologyElectronic supplementary information (ESI) available: Crystallographic data in the form of CIF files, selected bond lengths and bond angles for compounds 1–5, and additional characterization data including thermogravimetric analysis and experimental and simulated powder XRD patterns. CCDC reference numbers 783947–783951. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c0ce00881h

Through hydrothermal treatment, a series of new 3D noninterpenetrating cobalt(iii)-lanthanide(iii) heterometallic coordination assemblies bearing 2,2′-bipyridine-4,4′-dicarboxylate (H2bpdc) ligands, CoLn2(bpdc)3(NO3)3(H2O)6·3.5H2O (Ln = Gd (2), Eu (3), Sm (4), La (5)), have been obtained which may be regarded as being derived from Co2(Hbpdc)2(bpdc)2(H2O)2·2H2O (1) with one-dimensional (1D) zigzag chains. The results of single-crystal X-ray analysis and the X-ray photoelectron spectroscopy study show that each Co center in all of the compounds is located in six-coordinate octahedral surroundings, and exhibits the trivalent oxidation state. Compounds 2–5possess isostructural 3D NaCl-type frameworks containing Ln2O16building blocks, exhibiting square pores with dimensions of ca.8 × 8 Å2along the [010] direction, which are occupied by nitrate anions and non-coordinated water molecules. The frameworks of 2–5are stable up to ca.300 °C followed by removal of the coordinated and uncoordinated water molecules, as is evident from the associated weight loss. The magnetic and gas adsorption properties for the Co(iii)-Gd(iii) system have been investigated. [ABSTRACT FROM AUTHOR]