Lanthanide metal–organic frameworks with 2,2′-bipyridine-polycarboxylic acid: Synthesis, crystal structures and fluorescent properties

Four lanthanide metal–organic frameworks, namely, [{[Ln5(bptc)3(Hbptc)(H2O)12]·4H2O}n (Ln = Eu, 1; Gd, 2; Tb, 3) and {[Eu(bptc′)]}n (4), (H4bptc = 2,2′-bipyridine-3,3′,6,6′-tetracarboxylic acid, H3bptc′ = 2,2′-bipyridine-3,6,6′-tricarboxylic acid) have been hydrothermally synthesized. Compounds 1–4 were structurally characterized by IR spectra, thermogravimetric analyses and single-crystal X-ray diffractions. Complexes 1–3 are the isostructural...