Sparkle model and intensity parameters of the Eu(3-amino-2-carboxypyridine-N-oxide)33H2O complex

The sparkle model for structural calculation of lanthanide complexes (SMLC) was applied to the Eu(3-aminopyridine-2-carboxylic acid N-oxide)(3)H2O, a new lanthanide complex recently synthesized. For the calculation of the electronic spectra of the complexes, the sparkle is replaced by a point charge with the ligands held in the positions as determined by the SMLC, and uses an INDO/S-CI model. A good agreement between theoretical and experimental UV absorption spectra of the complex has been obtained. This result increased our confidence in the predicted structure. The optimized spherical coordinates of the ligands were then used to perform theoretical predictions of the Judd-Ofelt intensity parameters (Omega (lambda),lambda = 2 and 4), the D-5(0) --> F-7(0)/D-5(0) --> F-7(2) intensity ratio and the D-5(0) --> F-7(1) transition splitting using the simple overlap model (SOM). The satisfactory results obtained in this system are an indication that both SMLC and SOM can lead to reliable prediction-of complex structure and 4f-4f intensities. (C) 2001 Elsevier Science B.V. All rights reserved.