RESUMEN
Four novel three-dimensional (3D) 4d-4f heterometal-organic compounds, [LnCd2(Pbc)4(Meimdc)(H2O)]·3H2O (Ln = Eu, 1a; Tb, 1b; Sm, 1c; Dy, 1d) (HPbc = 4-(4-pyridinyl)benzoic acid; H3Meimdc = 2-methyl-1H-4,5-imidazole-dicarboxylic acid), have been successfully prepared by a hydrothermal method. All the compounds are isostructural and show three-dimensional microporous pillar-layered structures with uncoordinated carboxylate sites hung in the channels. Compound 1a possesses excellent chemical stability. The luminescent investigations show that compounds 1a, 1b, 1c, and 1d display the characteristic emission bands of Ln3+ ions. Compound 1a exhibits a good potential as a luminescent sensor material for multi-responsive Ag+, Cu2+, Zn+, Co2+, and Ni2+ cations and some organic amines. Interestingly, 1a can capture Ag+, Cu2+, Zn+, Co2+, and Ni2+ cations and shows cation-dependent colorimetric response, which indicates the potential for naked sensing.
RESUMEN
A series of lanthanide-organic frameworks [Ln(Himdc)(ina)(H2O)]n (Ln = Eu 1a; Sm 1b; and Nd 1c, H3imdc = imidazole-4,5-dicarboxylic acid, Hina = isonicotinic acid) were synthesized under hydrothermal conditions. All compounds 1a-1c consist of a 3D microporous lanthanide carboxylate ([Eu(COO)3]n) framework and uncoordinated Lewis basic pyridyl and imidazole groups hung in the channels. The luminescence investigations show that the compound 1c displays an interesting NIR luminescence property. The compound 1a exhibits a good potential as a luminescent multi-responsive sensing material for Fe3+ ions and Cr2O72- anions.