Theoretical spectroscopic study of europium tris(bipyridine) cryptates.

A series of europium cryptates are studied, using semiempirical methods to predict electronic and spectroscopic properties. The results are compared with theoretical (DFT) and experimental results published by Guillaumont and co-workers (ChemPhysChem2007, 8, 480). Triplet energies calculated by semiempirical methods have errors similar to those obtained by TD-DFT methodology but hundreds of times faster. Moreover, the semiempirical results not only reproduce well the experimental values but also help explain the low values of quantum efficiency observed for these complexes.