Mechanistic Investigation of Inducing Triboluminescence in Lanthanide(III) β-Diketonate Complexes

Abstract

In this work, we synthesized a series of lanthanide(III) β-diketonate complexes to investigate the induction of triboluminescence. Triboluminescence (TL) spectra, solid-state emission spectra, and luminescence lifetimes of the complexes were obtained to prove consistent emitting species for steady-state and triboluminescence measurements. Detailed analyses of the crystal lattice packing were conducted in an attempt to correlate crystal symmetry, gas discharge, and structural arrangements with "triboexcitation", and it is found that either noncentrosymmetric or centrosymmetic compounds can be TL-active. Furthermore, an intensely TL compound, Eu(dbm)TMP, was achieved, and its light emission can be seen under daylight upon mechanical stress.

Triboluminescence of a new family of CuI–NHC complexes in crystalline solid and in amorphous polymer films

“…3,[41][42][43] However, there are currently many examples of centrosymmetric crystals showing TL properties, attributed to a number of possible reasons: including the generation of oppositely charged planes in ionic crystalline compounds upon fracture, or the presence of defects or disorders in the crystal structure leading to local non-centrosymmetry. [44][45][46][47][48][49][50][51][52] The complexes 1, 2, and 3a-d are all ionic compounds, and disordered fragments are clearly present in some of the crystal structures (1 and 3b-d), so neither of these effects can be ruled out as the source of the TL effect. However, it is clear that the centrosymmetry, or lack of it, in the parent space group of a crystal is not tied to TL emission.…”

Effective photosensitized, electrosensitized, and mechanosensitized luminescence of lanthanide complexes

“…Quantitative estimation of the triboluminescence efficiency is important to clarify the mechanism of triboluminescence and to develop strong triboluminescent materials. Generally, the drop-tower method is used to estimate the triboluminescence efficiency [173][174][175] . However, it is difficult to use the drop-tower method as a quantitative estimation (for calculations of the radiative and non-radiative rate constants).…”

Progress of Research on Organic/Organometallic Mechanoluminescent Materials

“…近年 来, 有机/金属有机力致发光材料因其种类繁多、可修饰 性强等优点而备受关注. 人们通常认为有机/金属有机 ML 材料一般具有非中心对称结构和压电性质, 然而其 发光机理尚不明确 [22,39,46,47] , 从而导致该领域发展缓慢.…”