Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
Faculty of Engineering, Hokkaido University, Kita-13 Jo, Nishi-8 Chome, Sapporo, Hokkaido, 060-8628, Japan.
Angew Chem Int Ed Engl. 2017 Jun 12;56(25):7171-7175. doi: 10.1002/anie.201703638. Epub 2017 May 16.
Luminescence upon the grinding of solid materials (triboluminescence, TL) has long been a puzzling phenomenon in natural science and has also attracted attention because of its broad application in optics. It has been generally considered that the TL spectra exhibit similar profiles as those of photoluminescence (PL), although they occur from distinct stimuli. Herein, we describe for the first time a large spectral difference between these two physical phenomena using lanthanide coordination polymers with efficient TL and PL properties. They are composed of emission centers (Tb and Eu ions), antenna (hexafluoroacetylacetonate=hfa), and bridging ligands (2,5-bis(diphenylphosphoryl)furan=dpf). The emission color upon grinding (yellow TL) is clearly different from that upon UV irradiation (reddish-orange PL) in Tb /Eu -mixed coordination polymers [Tb,Eu(hfa) (dpf)] (Tb/Eu=1). The results directly indicate the discrete excitation processes of PL and TL.
固体材料研磨时的发光现象（摩擦发光，TL）长期以来一直是自然科学中的一个令人困惑的现象，由于其在光学领域的广泛应用，也引起了人们的关注。人们普遍认为，TL 光谱与光致发光（PL）的光谱相似，尽管它们是由不同的刺激产生的。在这里，我们首次使用具有高效 TL 和 PL 性能的镧系配合物聚合物描述了这两种物理现象之间的巨大光谱差异。它们由发射中心（Tb 和 Eu 离子）、天线（六氟乙酰丙酮=hfa）和桥联配体（2,5-双（二苯基膦基）呋喃=dpf）组成。在 Tb/Eu-混合配位聚合物[Tb，Eu(hfa)(dpf)]（Tb/Eu=1）中，研磨时的发射颜色（黄色 TL）明显不同于紫外光照射时的发射颜色（橙红色 PL）。结果直接表明了 PL 和 TL 的离散激发过程。
