Effective photosensitized, electrosensitized, and mechanosensitized luminescence of lanthanide complexes

Abstract

The 4f-4f emission of Tb(III), Eu(III), and Sm(III) complexes plays an important role in the design of monochromatic green, red, and deep-red luminescent materials for displays, lighting, and sensing devices. The 4f-4f emission of Yb(III), Nd(III), and Er(III) complexes is observed in the near-infrared (IR) region for bioimaging and security applications. However, their absorption coefficients are extremely small (ε < 10 L mol −1 cm −1 ). In this review, photosensitized luminescent lanthanide(III) complexes containing organic chromophores (ligands) with large absorption coefficients (ε > 10,000 L mol −1 cm −1 ) are introduced. Organic molecular design elements, including (1) the control of the excited triplet (T 1 ) state, (2) the effects on the charge-transfer (CT) band, and (3) the energy transfer from metal ions for effective photosensitized luminescence, are explained. The characteristic electrosensitized luminescence (electroluminescence) and mechanoluminescence (triboluminescence) of lanthanide(III) complexes are also explained. Lanthanide(III) complexes with well-designed organic molecules are expected to open avenues of research among the fields of chemistry, physics, electronics, and material science.

Near‐IR Luminescent YbIII Coordination Polymers Composed of Pyrene Derivatives for Thermostable Oxygen Sensors

“…The coordination of Yb III ions by the TIAPy ligands was confirmed on the basis of shifts in the IR peaks due to the C=O groups (TIAPy: 1685 cm À1 ,Y b III -TIAPy:1 538 cm À1 )a sw ell as ESI-MS data. The main small-angle peaks for Yb III -TIAPy at 8.408,9 .228,1 2.738,a nd 14.388 are very similart ot hose reported for three-dimensional Eu 2 (H 2 -TIAPy)(H 2 O) 4 with porous cavities ( Figure S1). [16] The IR peaks of Yb-TIAPy prepared by hydrothermal reactiona re also similar to those of Yb III -TIAPyp repared by complexation ( Figure S2).…”

“…This phenomenon is due to energy transfer between excited triplet states associated with p-p* transitions in the aromatic ligandsand 4f orbitals in the lanthanide(III)i ons. [4] However,t hese excited triplet states are quenched by the triplet state of atmospheric oxygen, such that the emissioni ntensity of such materials is reduced in the presenceo fo xygen. Based on this photophysicalq uenching, lanthanide(III) complexes with aromatic ligands may potentially be appliedi no xygen sensors.…”

Enhanced luminescence and tunable magnetic properties of lanthanide coordination polymers based on fluorine substitution and phenanthroline ligand

“…10 The magnetic properties of these lanthanides continue to be an attractive research eld in high-density data storage technologies and molecular spintronics. However, the luminescence intensity is oen quenched by the non-radiative exchange of electronic energy of Ln(III) to the high vibration modes of O-H and C-H bonding, 11 which are detrimental to their application in displays, light signal transmission, and sensing devices. The search for a new class of magneto/luminescent compounds is a great challenge.…”

Luminescent Thermometers: From a Library of Europium(III) β‐Diketonates to a General Model for Predicting the Thermometric Behaviour of Europium‐Based Coordination Systems

“…L1-based Eu complexes have shown outstanding thermometric properties in TSP applications. [20,21] Since it is well-known that the expansion of πconjugation in aromatic systems leads to a shift of the absorption band towards the visible range of the electromagnetic spectrum -i. e. a decrease in the energy of singlet and triplet excited states [22] -we designed two new ligands, L2 and L3, in which one of the thienyl groups is replaced by a polycyclic aromatic hydrocarbon (PAH) moiety: naphthyl and phenanthryl for L2 and L3, respectively (SI, Figure S1 Figure S5, 6 Table S1-2). Throughout the text, they will be labelled as EunE and EunT, where n is the number that identifies the ligand and E or T refers to EtOH or TPPO, respectively.…”