Abstract
Four new three-dimensional isostructural lanthanide-cadmium metal-organic frameworks (Ln-Cd MOFs), [LnCd2(imdc)2(Ac)(H2O)2] H2O (Ln=Pr (1), Eu (2), Gd (3), and Tb (4); H3imdc=4,5-imidazoledicarboxylic acid; Ac=acetate), have been synthesized under hydrothermal conditions and characterized by IR, elemental analyses, inductively coupled plasma (ICP) analysis, and X-ray diffraction. Single-crystal X-ray diffraction shows that two LnIIIions are surrounded by four CdIIions to form a heteronuclear building block. The blocks are further linked to form 3D Ln-Cd MOFs by the bridging imdc3-ligand. Furthermore, the left- and right-handed helices array alternatively in the lattice. Eu-Cd and Tb-Cd MOFs can emit characteristic red light with the EuIIIion and green light with the TbIIIion, respectively, while both Gd-Cd and Pr-Cd MOFs generate blue emission when they are excited. Different concentrations of Eu3+and Tb3+ions were co-doped into Gd-Cd/Pr-Cd MOFs, and tunable luminescence from yellow to white was achieved. White-light emission was obtained successfully by adjusting the excitation wavelength or the co-doping ratio of the co-doped Gd-Cd and Pr-Cd MOFs. These results show that the relative emission intensity of white light for Gd-Cd:Eu3+,Tb3+MOFs is stronger than that of Pr-Cd:Eu3+,Tb3+MOFs, which implies that the Gd complex is a better matrix than the Pr complex to obtain white-light emission materials.
Original language | English |
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Pages (from-to) | 95-100 |
Number of pages | 6 |
Journal | Chemistry - An Asian Journal |
Volume | 8 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jan 2013 |
Keywords
- crystal structures
- ligands
- luminescence
- metal-organic frameworks
- white-light emission
ASJC Scopus subject areas
- General Chemistry