Photophysics of Ce3+ cryptates

The species [Ce3+ ⊂ 2.2.1] and [Ce3+ ∉ 2.2.2] show efficient ultraviolet luminescence at room temperature. The spectra have been analysed and are discussed. The Stokes shift of the emission is smaller in the solid state than in solution. This is discussed in connection with the configuration of the species. In solid [Ce3+ ⊂ 2.2.1]Cl3·2H2O energy transfer between the cryptate species leads to a diffusion length of about 60 Å. A comparison with the related Eu2+ cryptates is made. The crystal-field splitting of the excited 5d level is derived and compared for these cryptates and some crown-ether complexes. © 1987.