High-resoln. excitation and luminescence were measured at 296 and 77 K. Eu3+ sites of Et2NH2+Eu(Bz2CH)4- were probed. The 5D0?F0 excitation spectrum of the complex displays 3 max. at room temperature and splits into 5 max. at 77 K. A series of similar spectra arise from slightly unequiv. Eu(Bz2CH)4- moieties differing in the disorder of Ph rings, experiencing slightly different crystal field effects. This shows the sensitivity of Eu3+ as conformational probe in the solid state.

Key words: METHANE P, LUMINESCENT SPECTRA, BENZENECARBOXYLIC ACID P, EXCITED STATE, DIETHYLAMINE P, CRYSTAL FIELD THEORY, EUROPIUM COMPLEX, FLUOROSPECTROPHOTOMETRY, LIGAND FIELD THEORY