The optical excitation and emission spectra of Eu(III) in [EuxLa1-x(AP
)(6)](ClO4)(3) centrosymmetric complex were measured. The vibronic tra
nsitions were observed in excitation and emission spectra. Following t
he vibrational analysis of the infrared and Raman spectra of [PrxLa1-x
(AP)(6)](ClO4)(3), the assignment of [EuxLa1-x(AP)(6)](ClO4)(3) vibron
ics was given. The concentration effect on excitation and emission spe
ctra was investigated. It was found that the vibronic intensities were
changed upon the concentration effect. The intensive charge transfer
bands were observed in blue region. Their intensities decreased with i
ncreasing concentration.