Some Properties of Europium β-diketone Chelates I (Synthesis and Fluorescent Properties)

As the organic laser materials, tetrakis europium β-diketone chelates have been prepared by using several β-diketones which contain a trifluoromethyl group as well as an aromatic hydrocarbon such as naphthalene, phenanthrene, anthracene, or compounds substituted at the para position of a benzene ring. Absorption and excitation spectra, fluorescence quantum yields, and fluorescence lifetimes of these europium chelates have been obtained. Except for the europium chelates of β-diketones derived from benzylideneacetone (EuBZDTFA) and anthracene (Eu9ATFA), these europium β-diketone chelates show strong red fluorescence characteristic of Eu3+ ion at room temperature both in solution and in crystalline powders. EuBZDTFA does not fluoresce till the temperature is lowered to about -80°C, and Eu9ATFA never fluoresces even at the liquid nitrogen temperature.