LUMINESCENCE OF DIVALENT EUROPIUM CROWN COMPLEXES IN VARIOUS SOLVENTS AND AT VARIOUS TEMPERATURES

The influence of solvents and temperature on the luminescence properties of divalent europium complexes with crown ethers has been studied. The luminescence spectrum of a 18-C-6 complex is much influenced by the nature of the solvents, but that of a 15-C-5 complex is not affected. Temperature increases from 77 K drastically decrease the emission intensity of a EuBr//2 solution. The emission intensity of the 18-C-6 complex is reduced less while that of the 15-C-5 complex is barely modified. These phenomena seem to be due to structural differences of the Eu**2** plus complexes.