Triboluminescence and crystal structures of nonionic europium complexes

The triboluminescence of three non-ionic europium complexes, Eu(TTA)3·bipy (1), Eu(TTA)3·dia (2) and Eu(DBM)3·dmbp·H2O (3) (TTA = 2-thenoyltrifluoroacetonate, DBM = dibenzoylmethanate, bipy = 2,2′-bipyridine, dia = 4,5-diazafluoren-9-one, dmbp = 4,4′-dimethyl-2,2′-bipyridinate), was observed. Structure determinations of 1 and 3 were carried out. The triboluminescence maxima of 1 and 2 are similar to those of their photoluminescence. The disorder of the thienyl ring and CF3 groups in 1 and the disorder of water in the packing of 3 may be responsible for their triboluminescent activity.