Versatile frameworks constructed from divalent metals and 1,2,3,4-butanetetracarboxylate anion: syntheses, crystal structures, luminescence and magnetic properties

Abstract

Nine new coordination polymers, namely [Cu(BTCA)_0.5(H₂O)₃]·2H₂O (1), [Ni₂(BTCA)(H₂O)₅]·2H₂O (2), [Zn(BTCA)_0.5(H₂O)₂]·0.5H₂O (3), [Mn(BTCA)_0.5(bipy)(H₂O)] (4), [Mn(BTCA)_0.5(phen)(H₂O)] (5), [Zn(BTCA)_0.5(obib)]·2.5H₂O (6), [Zn(BTCA)_0.5(pbib)_0.5]·H₂O (7), [Zn(BTCA)_0.5(bbi)]·H₂O (8) and [Co(BTCA)_0.5(bbi)]·H₂O (9), where bipy = 2,2′-bipyridine, phen = 1,10-phenathroline, obib = 1,2-bis(imidazol-1-ylmethyl)benzene, pbib = 1,4-bis(imidazol-1-ylmethyl)benzene, bbi = 1,1′-(1,4-butanediyl)bis(imidazole), and BTCA = 1,2,3,4-butanetetracarboxylate anions, were synthesized. Compounds 1 and 2 possess 2D polymeric structures, while compound 3 has a 3D network. Compounds 4 and 5 exhibit infinite 1D chain structures, and the adjacent chains are connected through π–π interactions between the aromatic rings of bipy or phen ligands. Both of the 3D frameworks of 6 and 7 are built from 2D zinc-carboxylate layers stretched by bis(imidazole) ligands. Compounds 8 and 9 are isostructural and show 3-fold interpenetrated α-Po structures. The thermal stabilities of 1–9 were studied by thermogravimetric analysis. The luminescent properties for 6–8 in the solid states, and magnetic property for 9 are also discussed in detail.