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Luminescence Tuning and White‐Light Emission of Co‐doped Ln–Cd–Organic Frameworks
Author(s) -
Ablet Ayjamal,
Li ShuMu,
Cao Wei,
Zheng XiangJun,
Wong WingTak,
Jin LinPei
Publication year - 2013
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201200813
Subject(s) - isostructural , lanthanide , luminescence , cadmium acetate , crystallography , ion , doping , chemistry , metal organic framework , crystal structure , materials science , analytical chemistry (journal) , cadmium , optoelectronics , organic chemistry , adsorption , chromatography
Four new three‐dimensional isostructural lanthanide–cadmium metal–organic frameworks (Ln–Cd MOFs), [LnCd 2 (imdc) 2 (Ac)(H 2 O) 2 ]⋅H 2 O (Ln=Pr ( 1 ), Eu ( 2 ), Gd ( 3 ), and Tb ( 4 ); H 3 imdc=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 Ln III ions are surrounded by four Cd II ions to form a heteronuclear building block. The blocks are further linked to form 3D Ln–Cd MOFs by the bridging imdc 3− 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 Eu III ion and green light with the Tb III ion, respectively, while both Gd–Cd and Pr–Cd MOFs generate blue emission when they are excited. Different concentrations of Eu 3+ and Tb 3+ 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:Eu 3+ ,Tb 3+ MOFs is stronger than that of Pr–Cd:Eu 3+ ,Tb 3+ MOFs, which implies that the Gd complex is a better matrix than the Pr complex to obtain white‐light emission materials.