Article pubs.acs.org/JACS
Intraligand Charge Transfer Sensitization on Self-Assembled Europium Tetrahedral Cage Leads to Dual-Selective Luminescent Sensing toward Anion and Cation Cui-Lian Liu,† Rui-Ling Zhang,‡,§ Chen-Sheng Lin,† Li-Peng Zhou,† Li-Xuan Cai,† Jin-Tao Kong,† Song-Qiu Yang,‡ Ke-Li Han,*,‡ and Qing-Fu Sun*,† †
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, People’s Republic of China ‡ State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China § University of the Chinese Academy of Sciences, Beijing 100049, People’s Republic of China S Supporting Information *
ABSTRACT: Luminescent supramolecular lanthanide edifices have many potential applications in biology, environments, and materials science. However, it is still a big challenge to improve the luminescent performance of multinuclear lanthanide assemblies in contrast to their mononuclear counterparts. Herein, we demonstrate that combination of intraligand charge transfer (ILCT) sensitization and coordination-driven self-assembly gives birth to bright EuIII tetrahedral cages with a record emission quantum yield of 23.1%. The ILCT sensitization mechanism has been unambiguously confirmed by both time-dependent density functional theory calculation and femtosecond transient absorption studies. Meanwhile, dual-responsive sensing toward both anions and cations has been demonstrated making use of the ILCT transition on the ligand. Without introduction of additional recognition units, high sensitivity and selectivity are revealed for the cage in both turn-off luminescent sensing toward I− and turn-on sensing toward Cu2+. This study offers important design principles for the future development of luminescent lanthanide molecular materials.
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tions in various fields, such as photoelectric devices, chemosensors, and bioimaging.8 In nature, direct excitation of lanthanide ions is very difficult due to the small molar extinction coefficient (
