Triboluminescence of A New Europate Complex

A new europium (Ⅲ) complex Eu(HFNH) 3Phen (HFNH: 4, 4, 5, 5, 6, 6, 6-heptafluoro-1-(2-naphthyl)hexane-1,3-dione; phen: 1,10-phenanthroline) was synthesized and its triboluminescent phenomenon was observed. Photoluminescence and triboluminescence spectra were successfully determined. The most intense triboluminescent emission originates from the transition of the central Eu 3+ ion from 5D 0 level to 7F 2 level. The triboluminescent spectrum is basically similar to that of photoluminescence, which correlates with the disorders of F atoms.

Interdiscipline between optoelectronic materials and mechanical sensors:Recent advances of organic triboluminescent compounds and their applications in sensing

Triboluminescence,also as known as mechanoluminescence,is an attractive optical behavior that means the light emitted from specific organic and inorganic materials when they are subjected to external forces,such as crushing,deformation,cleaving,vibration.Inorganic triboluminescent materials show great potential for applications in sensing,such as stress sensing,damage detection.However,the triboluminescent mechanism of organic materials should be pushed further as well as their application.In this review,we summarized the history of development and possible mechanism of organic triboluminescent materials,and discussed various applications in sensing field.At the same time,inspired by the existing research progress in inorganic triboluminescent materials,we proposed the flourishing development prospects of organic triboluminescent materials in stress sensors,movement monitoring,imaging stress distribution,visualization of crack propagation,structural diagnosis,and other fields.

Crystal and Molecular Structure of Triboluminescent Complex Eu(NO_3)(TTA)_2(TPPO)_2

Eu(NO_3)(TTA)_2(TPPO)_2 (TTA=thenoyltrifluoroacetone,TPPO=triphenylphosphine oxide), M=1212.90,triclinic P1,a=1.1081(2)nm,b=1.1857(2)nm,c=1.2580(2)nm,α=65.54(1)°,β=77.91 (1)°,γ=61.99(1)°;Z=1,V=1.3281(4)nm^3,D_c=1.47g/cm^3,μ_(MoK_α)=14.1 cm^(-1).The crystal desplays triboluminescence upon fracture.Structure study shows that the crystal is noncentrosymmetric and no disor- der is found.It is concluded that the polarity of crystals is necessary for the observation of triboluminescence.

Triboluminescent Complexes of Rare Earth Ⅱ.Mixed-ligand Complexes of Eu^(3+) with Thenoyltrifluoroacetone and Pyridine-N-Oxide or its Substitutive Derivatives

Five triboluminescent mixed-ligand complexes of Eu^(3+)with thenoyltrifluoroacetone(TTA)and pyridine-N-oxide or its substitutive derivatives have been prepared.They are all pale yellow crystalline com- pounds with the formula of Eu(TTA)_3·L(L=py NO.2-pie NO,3-pie NO,4-pic NO,bipy N_2O_2).Their physico-chemical properties have been studied with conductometry,UV and IR absorption and fluorescence spectroscopy.Once the complexes are touched or rubbed by a glass rod,they emit strong red triboluminescent light which is similar to the characteristic fluorescence of Eu^(3+).

Recent progress in organic mechanoluminescent materials

Mechanoluminescence（ML） refers to the light emission from various organic and inorganic materials upon mechanical stimulus. As a new class of smart materials, mechanoluminescent materials are widely applicable for fluorescence switches, mechanosensors, security papers, optoelectronic devices and data storage etc. In the past few years, systematic investigations have been carried out, resulting in the production of a variety of mechanoluminescent materials. In this review, recent progress in pure organic mechanoluminescent materials is summarized, including mechanofluorescent and triboluminescent effects from conjugated small molecules.