1 research outputs found
Intraligand Charge Transfer Sensitization on Self-Assembled Europium Tetrahedral Cage Leads to Dual-Selective Luminescent Sensing toward Anion and Cation
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 Eu<sup>III</sup> 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<sup>–</sup> and turn-on sensing toward Cu<sup>2+</sup>. This
study offers important design principles for the future development
of luminescent lanthanide molecular materials