Electronic Structure and Photoluminescence Properties of Eu(η⁹-C₉H₉)₂

Abstract

The electronic structure of Eu 2+ compounds results from a complex combination of strongly correlated electrons and relativistic effects as well as weak ligand−field interaction. There is tremendous interest in calculating the electronic structure as nowadays the Eu 2+ ion is becoming more and more crucial, for instance, in lighting technologies. Recently, interest in semiempirical methods to qualitatively evaluate the electronic structure and to model the optical spectra has gained popularity, although the theoretical methods strongly rely upon empirical inputs, hindering their prediction capabilities. Besides, ab initio multireference models are computationally heavy and demand very elaborative theoretical background. Herein, application of the ligand−field density functional theory (LFDFT) method that is recently available in the Amsterdam Modeling Suite is shown: (i) to elucidate the electronic structure properties on the basis of the multiplet energy levels of Eu configurations 4f 7 and 4f 6 5d 1 and (ii) to model the optical spectra quite accurately if compared to the conventional time-dependent density functional theory tool. We present a theoretical study of the molecular Eu(η 9-C 9 H 9) 2 complex and its underlying photoluminescence properties with respect to the Eu 4f−5d electron transitions. We model the excitation and emission spectra with good agreement with the experiments, opening up the possibility of modeling lanthanides in complex environment like nanomaterials by means of LFDFT at much-reduced computational resources and cost.

DFT exchange: sharing perspectives on the workhorse of quantum chemistry and materials science

“…See, for example, the case of the Eu(η 9 -C 9 H 9 ) 2 complex, for which the 30030 multiplet energy levels have been calculated. 413 (3.6.11) Krylov : To properly deal with symmetry breaking, we need to look at properties that are rigorously defined -for example, it is difficult to discuss what spin symmetry means within DFT because S 2 is a two-electron operator. 414 So spin-contaminated (as traditionally computed) KS DFT or TDDFT solutions might, in fact represent the correct spin densities of the spin-pure correlated many body wave functions -for example, an open shell doublet radical (such as CH 3 ) in which the unpaired electron has alpha spin, is known to have areas with the excess beta-spin density.…”

“…See, for example, the case of the Eu(Z 9 -C 9 H 9 ) 2 complex, for which the 30 030 multiplet energy levels have been calculated. 413 3.6.11 Krylov. To properly deal with symmetry breaking, we need to look at properties that are rigorously defined -for example, it is difficult to discuss what spin symmetry means within DFT because S 2 is a two-electron operator.…”

“…See, for example, the case of the Eu(η 9 -C 9 H 9 ) 2 complex, for which the 30 030 multiplet energy levels have been calculated. 413 …”

Back to the future of organolanthanide chemistry

“…4). 36,77,[116][117][118][119][120][121][122] With the recent introduction of novel organometallic architectures as supporting ligands, such as large ring ligands, 25,36,37 further development in this field is likely to be expected. The development of ligand structures inducing long luminescence lifetimes is highly desirable for lightpromoted photoredox reactions to maximize the probability of an electron transfer from the organolanthanide complex to the substrate.…”

Influence of Golden Nanoparticles on the Incorporation of Eu2+ into BaI2 and Defect Concentration

“…Development of effective scintillator materials with low-cost manufacturing still remains a current issue due to the absence of an ideal phosphor [1]. The alkaline-earth binary halides, such as CaI 2 , SrI 2 , BaCl 2 , BaBr 2 and BaI 2 , represent, thanks to their high effective atomic numbers (Z ~50), high light yields (up to 100,000 photon/MeV) and low-cost synthesis, making them promising materials for scintillation radiation detectors [2][3][4][5][6][7]. To enhance their luminescent properties, alkaline-earth halides require activation by a dopant.…”