Triboluminescence Phenomenon Based on the Metal Complex Compounds—A Short Review

Triboluminescence (TL) is a phenomenon of light emission resulting from the mechanical force applied to a substance. Although TL has been observed for many ages, the radiation mechanism is still under investigation. One of the exemplary compounds which possesses triboluminescent properties are copper(I) thiocyanate bipyridine triphenylphosphine complex [Cu(NCS)(py)2(PPh3)], europium tetrakis dibenzoylmethide triethylammonium EuD4TEA, tris(bipyridine)ruthenium(II) chloride [Ru(bpy)3]Cl2, and bis(triphenylphosphine oxide)manganese(II) bromide Mn(Ph3PO)2Br2. Due to the effortless synthesis route and distinct photo- and triboluminescent properties, these compounds may be useful model substances for the research on the triboluminescence mechanism. The advance of TL studies may lead to the development of a new group of sensors based on force-responsive (mechanical stimuli) materials. This review constitutes a comprehensive theoretical study containing available information about the coordination of metal complex synthesis methodologies with their physical, chemical, and spectroscopic properties.