Triboluminescence and crystal structure of the complex [Eu(MBA) Dipy] (HMBA).

The atomic structure of the crystals [Eu(MBA) Dipy] (HMBA) (MBA-аnion toluic acid, Dipy-2,2'-dipyridyl, HMBA-toluic acid), displaying intensive luminescence and triboluminescence was determined using single crystal X-ray diffraction analysis. The triclinic centrosymmetric crystals have the following parameters: a = 10.620(2), b = 11.849(2), c = 14.9868(2) Å, α = 68.297(1), β = 76.172(1), γ = 80.378(1)°, sp.gr. P 1, Z = 1, ρ  = 1.537 g/cm . The structure belongs to the insular type and is presented as the isolated complex Eu -dimeric formations and outer-sphere HMBA. The structural aspects of the observed luminescence and triboluminescence properties of the compound were discussed, and the cleavage plane role in the process of the crystal destruction was revealed.