Synthesis, characterization and thermogravimetric study of the complexes [Eu(12-crown-4)·phen2]·X3 (phen = 1,10-phenanthroline; X = F, Cl, Br, SCN, ClO4 and NO3): Effect of the counter-ion on the thermal degradation profile

The complexes [Eu(12-crown-4)·phen2]·X3 (phen = 1,10-phenanthroline; X = F, Cl, Br, SCN, ClO4 and NO3) were synthesized and characterized by elemental analysis, UV–vis and IR spectroscopy. A thermogravimetric study was performed to evaluate the effect of the counter-ion on the thermal degradation profile of the [Eu(12-crown-4)·phen2]+3 complex cation. In general, the 1,10-phenanthroline molecules are the first to be released, showing that the crown ether molecule forms more stable bonds with the +3 cation. The fluorine complex sublimes and thus could be employed as a precursor for preparation of luminescent films.