PHOTOLUMINESCENCE AND MOLECULAR-STRUCTURE OF TETRAKIS(N,N-DIMETHYLDITHIOCARBAMATO)EUROPATE(III)

Photoexcitation of the sulfur(S)-to-europium(Eu) charge-transfer bands in Na[Eu(S2CNMe2)(4)].3.5H(2)O at the low temperature (< 100 K) leads to the D-5(0)-->F-7(J) (J=0-4) luminescence of Eu3+ as a result of th e energy transfer to the D-5(0) state. The luminescence and excitation spectra reveal the dithiocarbamato-ligand phonon assisted electronic transition involved in the small energy gap (similar to 1800 cm(-1)]) between the D-5(1) and D-5(0) levels. The luminescence lifetime (0.11 +/- 0.01 ms at 4.2 K) decreases with increasing temperature, probably due to the thermal crossover relaxation from D-5(0) to the S-->Eu char ge transfer states.