Crystal structure, luminescence, and triboluminescence of the complex [Eu$_{2}$(Quin)$_{4}$2H$_{2}$O2Dipy]$_{2}$(NO$_{3}$)$_{2}$H$_{2}$O

An atomic structure of crystals of the complex [Eu$_{2}$(Quin)$_{4}$2Н$_{2}$O2Dipy]$_{2}$ $\cdot$ 2(NO$_{3}$) $\cdot$ Н$_{2}$O, (Quin, anion of quinaldic acid; Dipy, 2,2'-dipyridyl), which exhibited intense luminescence and triboluminescence, has been investigated via the X-ray diffraction analysis. The structure of crystals of the compound appeared to be of an islelike type and were represented by two separate crystallographically independent complex dimers, outer-sphere [NO$_{3}$]$^{-1}$-groups, and water molecules. Structural aspects of the formation of the luminescent and triboluminescent properties of the compound have been discussed. The role of cleavage planes at crystal destruction has been established.