We have discovered room temperature photoluminescence in SM3+ and Pr3+ dithiocarbamate complexes. Surprisingly, these complexes exhibit more intense emission than those of the Eu3+, Tb3+, and Dy3+ analogues. The electronic absorption, excitation, and emission spectra are reported for the complexes [Ln(S2CNR2)(3)L] and NH2Et2[Ln(S2CNEt2)(4)], where Ln = Sm, Pr; R = ethyl, butyl, benzyl; and L = 1,10-phenanthroline, 2,2'-bipyridine, and 5-chloro-1,10-phenanthroline. The lowest ligand-localized triplet energy level (T-1) of the complexes are determined from the phosphorescence spectra of analogous La3+ and Gd3+ chelates. The luminescence decay curves were measured to determine the excited-state lifetimes for the Pr3+ and Sm3+ complexes. X-ray crystal structures of Sm((S2CNBu2)-Bu-i)(3)phen, Pr(S2CNEt2)(3)phen, and Pr((S2CNBu2)-Bu-i)(3)phen are also reported.
Synthesis, properties and structure of lanthanide complexes with N,N-diethyldithiocarbamate and 2,2′-bipyridyl
作者:Chengyong Su、Ning Tang、Minyu Tan、Kaibei Yu
DOI:10.1016/0277-5387(95)00247-p
日期:1996.1
Sm-Lu, Y; Et 2 Dtc = N,N-diethyldithiocarbamate; bipy = 2,2′-bipyridyl) have been prepared and characterized by chemical analysis, IR spectra, electronic spectra and conductivity measurements. The crystal and molecularstructures of [Er(Et 2 Dtc) 3 (bipy)] have been determined by single-crystal X-ray diffraction techniques. The central Er III atom is octa-coordinated and in a distorted dodecahedral
Systematic Behavior of Charge-Transfer Transitions and Energy Level Variation in Soft Donor Complexes of the Trivalent Lanthanides
作者:G. K. Liu、M. P. Jensen、P. M. Almond
DOI:10.1021/jp0558674
日期:2006.2.1
The systematic behavior of the charge-transfer (CT) energies in mixed 2,2'-bipyridyl (bipy), N,N-diethyldithiocarbamate (Et(2)dtc(-)) complexes of the trivalent lanthanides, Ln(Et(2)dtc)(3)(bipy), is investigated to understand the electronic structure of f-element complexes containing soft donor ligands. The energies of ligand to Ln(3+) CT are extremely low in this system, an effect attributed to the presence of the soft donor ligands. The lowest CT energy level for the Sm3+, Eu3+, and Yb3+ complexes falls into the visible range. In Eu(Et(2)dtc)(bipy), the Eu3+ ion becomes nonluminescent because the CT energy stretches below the metastable D-5(0) electronic state, whereas luminescence from the CT state and the 4f(13) F-2(5/2) state are observed in the Yb compound. The variation in the energy of the lowest level CT transition for the entire Ln(Et(2)dtc)(3)(bipy) series has been evaluated using the experimentally determined CT levels of the Sm3+, Eu3+, and Yb3+ compounds based on the systematic behavior of the lanthanides, which is invariant with respect to the type of ligand. The energy difference between the ground electronic states of the lanthanide ions and the ligand-centered valence band may also be calculated from these results.