Lanthanide benzoates: a versatile building block for the construction of efficient light emitting materials

Abstract

On account of their intrinsic chemical and spectroscopic properties, luminescent lanthanide molecular materials find potential applications in lighting, optical communications, photonics and biomedical devices. This perspective article summarizes some recent seminal research work on luminescent properties and structural aspects of a series of lanthanide benzoate complexes featuring Eu(3+) and Tb(3+) ions. In particular, when modified with light-harvesting moieties, benzoates have proven to be efficient sensitizers for lanthanide ions. The photoluminescence properties of the various lanthanide benzoate coordination compounds have also been correlated with the electronic states of the newly designed antenna molecules.

Synthesis, structural characterization and luminescent properties of a novel europium ternary complex Eu(2-A-4-CBA)3phen

“…Compounds containing some atoms, such as N, O, S, can be used as ligands. And in these ligands, the study of aromatic carboxylic acids [10][11][12] is more and more popular.…”

Synthesis, Structure, Photoluminescence, and Electroluminescence of Four Europium Complexes: Fabrication of Pure Red Organic Light‐Emitting Diodes from Europium Complexes

“…Although the luminescence of the europium ion can be efficient, the ion suffers from weak light absorption, because the electric‐dipole f–f transitions that result in light emission from the europium ion are parity‐forbidden, in spite of the opposite‐parity‐allowed magnetic‐dipole f–f transitions . One way to overcome the problem of the weak f–f absorption transition of the europium ion and to achieve bright emission is to surround the ion with adequate organic ligands able to harvest light and to subsequently transfer the electronic energy to the metal‐ion excited states, while simultaneously providing a rigid protective coordination shell for minimizing nonradiative deactivation , , . This indirect excitation process is known as the antenna effect or sensitization .…”

“…[12] One way to overcome the problem of the weak f-f absorption transition of the europium ion and to achieve bright emission is to surround the ion with adequate organic ligands able to harvest light and to subsequently transfer the electronic energy to the metal-ion excited states, while simultaneously providing a rigid protective coordination shell for minimizing nonradiative deactivation. [3,5,[13][14][15][16][17] This indirect excitation process is known as the antenna effect or sensitization. [18] It is also desirable that the coordination sphere of the europium ion is saturated with the ligand and protected from water molecules, which strongly bind to the europium ion and quench its luminescence.…”

Syntheses, Crystal Structures and Luminescent Properties of a Series of Ag-Ln Coordination Polymers

“…[6][7][8][9] However most of f-f transitions of Ln(III) ions are forbidden, their absorption coefficient is low and their luminescent intensity is weak. [10][11][12][13][14] Therefore, organic ligands absorbing UV light [15][16][17][18] and transition metal ions are introduced into the system to sensitize the luminescence of Ln(III) ions. [19][20][21][22][23][24] So far, there are many researches on the luminescent properties of 4d-4f complexes, and AgÀLn polymers have gained much attention due to two aspects.…”